Trump impeachment: GOP-led Senate rejects amendments, approves rules of trial After a marathon debate, the GOP-led Senate approved the rules of impeachment.

In a marathon session that began at 1 p.m. Tuesday and lasted nearly 13 hours into the early morning, the Republican-led Senate rejected all 11 Democratic-proposed amendments en route to approving the rules for the impeachment trial of President Donald Trump.

The only changes to the rules proposed Monday by Senate Majority Leader Mitch McConnell came earlier Tuesday when Republicans reversed their original call for arguments to take place over two days, and instead agreed that arguments would take place over a three-day period. McConnell also agreed to have evidence from the House inquiry automatically admitted as evidence in the Senate trial.

The rules were approved by a party-line vote, 53-47, after more than 12 hours of debate that left many Senate members exhausted by the time the Senate was adjourned shortly before 2 a.m.

Here is how the day unfolded:

1:55 a.m. Final amendments fail and vote on rules passes

Following the rejection of three additional amendments regarding the trail's timing and procedures, the Senate approved the rules of impeachment as put forth by Sen. McConnell.

The vote passed along party lines 53-47. The Senate then adjourned after nearly 13 hours.

1:19 a.m. 8th amendment to subpoena John Bolton fails following clash

The eighth amendment of the evening, on the question of whether to subpoena former National Security Advisor John Bolton to testify in the impeachment trial, failed along party lines, 53-47.

The vote followed a clash between impeachment manager Rep. Jerrold Nadler, D-N.Y., and White House counsel Pat Cipollone.

“Ambassador Bolton was appointed by President Trump and has stated his willingness to testify in this trial," Nadler said. "The question is whether the Senate will be complicit in the president's crimes by covering them up.”

Cipollone, in response, blasted Nadler's characterization, saying, "Mr. Nadler, you owe an apology to the president of the United States and his family, you owe an apology to the Senate, but most of all, you owe an apology to the American people.”

Chief Justice John Roberts, overseeing the trial, admonished both sides for the rhetoric.

The Senate is now debating additional amendments to the rules related to the trail's timing and procedures.

12:02 a.m. 7th amendment fails, on to the 8th amendment involving John Bolton

The seventh amendment of the evening, to "prevent the selective admission of evidence and to provide for appropriate handling of classified and confidential materials," again failed along party lines, 53-47.

The Senate will now take up the question of whether to subpoena former National Security Advisor John Bolton, who Democrats believe could further tie President Trump to the Ukraine affair.

11:21 p.m. 6th amendment fails, but debate continues

Chuck Schumer's sixth amendment, to subpoena testimony from Mick Mulvaney adviser Robert Blair and OMB official Michael Duffey, failed -- again along party lines.

And after a brief, five-minute break it was on to the seventh amendment of the evening to "prevent the selective admission of evidence and to provide for appropriate handling of classified and confidential materials."

The amendment would require "that if, during the impeachment trial of Donald J. Trump, any party seeks to admit evidence that has not been submitted as part of the record of the House of Representatives and that was subject to a duly authorized subpoena, that party shall also provide the opposing party all other documents responsive to that subpoena."

10:33 p.m. 5th amendment fails, onto the 6th

The fifth amendment proposed by Democrats -- to subpoena Department of Defense documents -- has failed along party lines, 53-47, and it is on to the sixth amendment.

Schumer's sixth amendment would subpoena testimony of Robert Blair, senior adviser to Mick Mulvaney, and Michael Duffey, a senior official at the Office of Management and Budget. Debate on the sixth amendment is starting now.

A brief "quorum call" was held earlier in which Sen. McConnell asked Sen. Schumer to dispense with the debate and "stack" the remaining amendment votes we have.

But Schumer responded that he believes each of the remaining votes are extremely important to the country and the Senate will take each of these votes. Schumer offered to put off the remaining votes until Wednesday, but McConnell did not agree to it.

9:53 p.m. Debate begins on 5th amendment

After a pause, a debate began on Schumer's fifth amendment to subpoena Department of Defense documents. Democratic Rep. Jason Crow kicked off talk and will reserve some of their one hour to respond to the White House argument on this amendment.

9:29 p.m. Schumer's 4th amendment fails

Schumer's 4th amendment -- to compel testimony from acting White House chief of staff Mick Mulvaney -- failed, in a 53-47 vote along party lines.

Just prior, Rep. Hakeem Jeffries, D-N.Y., had argued in favor of the amendment.

"President Trump’s total obstruction makes Richard Nixon look like a choir boy," he said, after listing the Nixon aides who cooperated with Congress during Watergate.

"Mr. Mulvaney was at the center of every stage of the president's substantial pressure campaign against Ukraine," Jeffries said. "Based on the extensive evidence that House did obtain, it is clear that Mulvaney was crucial in planning the scheme, executing its implementation and carrying out the coverup."

He said a fair trial "demands" that Mulvaney testify.

9:23 p.m. 'Can we please start?'

Add White House counsel Pat Cipollone to the name of those hoping for Tuesday night's proceedings to end.

Cipollone pleaded with senators to start the trial, hitting Democrats on the multiple amendments they are continuing to debate.

"If we keep going like this it will be next week," Cipollone said, prompting laughs from the Republican senators, including McConnell, who smirked through Cipollone’s remarks.

"We’re here to have a trial," he said.

8:03 p.m. White House comments on proceedings, motion to dismiss

Eric Ueland, the White House Legislative Affairs director, who has been in the chamber for the trial, left the door open to the Trump team putting forward a motion to dismiss as early as Wednesday.

"Such motions could be filed as late as 9 a.m. tomorrow morning," he told ABC News as he stepped out of the chamber.

it is unclear when such a motion would get a vote.

Ueland also said the president is being kept "constantly updated" while in Davos "and is very impressed" with his team’s performance.

"There is a very good infrastructure in place to keep the president updated -- while he's in Davos -- the ins and outs of what’s going on here on the floor," he said.

7:24 p.m. GOP-controlled Senate rejects Democrats' effort to subpoena OMB records

McConnell calls for a vote to table, or set aside, Schumer's amendment calling for the Senate to subpoena the Office of Management and Budget for documents related to the military aid to Ukraine.

The amendment is killed 53-47 along strict party lines -- just as happened with the two previous Democratic amendments.

Schumer announces a fourth amendment -- to subpoena testimony from acting White House Chief of Staff Mick Mulvaney.

With it still unclear how many more amendments Democrats might offer -- and how many more hours of debate that might mean -- the Senate then breaks for dinner.

As GOP senators leave the chamber -- many grabbing phones and furiously typing on their electronics -- they’re huddling just off the floor to enjoy a dinner of -- pizza.

7:10 p.m. A long day for senators, stuck in seats, listening to hours of arguments

The first long day of the president's impeachment trial has taken its toll on senators, who have been forced to sit in silence, relying on water and snacks to sustain them through hours of debate over the resolution setting the parameters for the impeachment trial.

The first person caught dozing was Republican Sen. Jim Risch of Idaho.

At about 5:30 p.m., as Rep. Val Demings, D-Fla., spoke in favor of an amendment to subpoena the State Department for records, Risch was slumped over with his head resting in his right hand, and appeared to be sleeping or close to it, though he stirred repeatedly to rub his eyes.

Risch perked up later as Jay Sekulow, a lawyer for President Trump, and Rep. Adam Schiff, the lead impeachment manager, took to the floor following Demings.

"What time is it?" Risch could be heard asking when Schiff appeared to run over the time allotted for the managers. He then started tapping the face of his wristwatch, which echoed through the chamber.

Other senators relied on gum and mints to stay alert. GOP Sen. Tim Scott of South Carolina was seen popping a mint into his mouth at about 6:10 p.m. Democratic Sen. Ron Wyden of Oregon was seen chewing on his pen.

The Senate is expected to break for dinner between 8 and 9 p.m. ET after a vote to table the Democrats' third amendment, which seeks to subpoena the Office of Management and Budget for records.

-- ABC's Benjamin Siegel

7:04 p.m. Sekulow argues Ukraine aid ultimately delivered without investigation announcement

The president's personal attorney and part of his defense team Jay Sekulow repeated arguments from Republicans that the Trump administration ultimately provided aid to Ukraine that was authorized by Congress and went further than aid provided by the Obama administration.

Sekulow said that the fact that the aid was ultimately provided without an announcement of an investigation into the Bidens or Burisma undercuts the Democrats' argument that President Trump held back the money for his own political benefit.

6:39 p.m. House manager Jason Crow argues OMB documents would show President Trump used national defense funds for his political benefit

House manager Jason Crow begins his argument in favor of the amendment to subpoena the Office of Management and Budget by sharing some of his personal history as an Army Ranger serving in Afghanistan and Iraq.

Crow is in his first term in Congress and served in the 82nd Airborne Division before joining the 75th Ranger Regiment, with which he served two tours in Afghanistan as part of the Joint Special Operations Task Force.

He says the decision to withhold military aid from Ukraine was "personal" to him and that OMB played a key role in the decisions to hold back aid approved by Congress.

"These documents would provide insight into critical aspects of the military-aid hold. They would show the decision-making process and motivations behind President Trump's freeze. They would reveal the concerns expressed by career OMB officials including lawyers that the hold was violating the law. They would expose the lengths to which OMB went to justify the president's hold," he says.

"They would reveal concerns about the impact of the freeze on Ukraine and U.S. national security. They would show senior officials repeatedly attempted to convince President Trump to release the hold. In short, they would show exactly how the president carried out the scheme to use our national defense funds to benefit his personal political campaign," Crow says.

6:20 p.m. Senate rejects second Democratic amendment, for State Department documents, also along party lines

Schiff appeals directly to the senators sitting silently in the chamber in his argument that they should vote to subpoena the State Department for additional evidence in the impeachment trial.

"You're going to have 16 hours to ask questions. Sixteen hours -- that's a long time to ask questions. Wouldn't you like to be able to ask about the documents during that 16 hours?"

Schiff references the "three amigos," three administration officials who took the lead in the administration's policy in Ukraine.

Although Ambassadors Kurt Volker and Gordon Sondland both testified as part of the House impeachment inquiry, Schiff pointed out that the third "amigo" - former Energy Secretary Rick Perry - has thus far refused to cooperate with investigators or provide any documents.

"Wouldn't you like to know? Don't you think the American people have a right to know what the third Amigo knew about this scheme?" Schiff asks.

McConnell calls for a vote to table Schumer's second amendment, calling for the Senate to subpoena the State Department for documents related to the administration's involvement in Ukraine and decision to withhold military aid. That amendment is tabled -- or killed-- along party lines, just his first one calling for White House witnesses was rejected.

Schumer then offers a third amendment to subpoena the Office of Management and Budget for documents.

Some color from our reporters inside the chamber watching from above in the press gallery:

During the defense’s statements, the most aggressive Republican note takers were GOP Sens. Murkowski and Collins (two of the four Republicans we are watching closely). The two women wrote for multiple minutes as White House counsel Pat Cipollone spoke.

A few aides have been walking on and off the floor to deliver notes to members, who for the most part remain quiet and attentive.

Also coming on and off the floor - Senate pages who have been vigorously delivering water glasses to both the House legal team and the members over the last few minutes.

-- ABC's Allison Pecorin

6:05 p.m. Chief Justice John Roberts has to be back at his first job tomorrow morning

Even as it's unclear how much longer the Senate will go tonight debating Democratic amendments, one of the few people in the chamber who will have to be back at work first thing tomorrow morning — running an entire branch of government — is the chief justice.

He’ll preside over oral arguments at the Supreme Court in a major case involving religion and school choice that public school unions say is “crucial” for their funding. That begins at 10 a.m.

The senators and other staff presumably won’t be back in business until midday when the trial’s opening arguments are expected to begin at 1 p.m. and Roberts will need to be back on the Senate dais as presiding officer.

-- ABC's Devin Dwyer

5:20 p.m. Democratic Rep. Val Demings argues Senate must subpoena State Department documents

House manager Val Demings is now making an argument in favor of an amendment to subpoena to State Department for documents related to Ukraine.

Demings, 62, made an impression in questioning witnesses when the testified before both the House Intelligence and Judiciary Committees.

Unlike the other House managers, Demings doesn't have a background as a litigator but she did work in the criminal justice system as the first female police chief in the Orlando Police Department, where she served for 27 years.

A Florida State University and Webster University graduate, Demings is the only member of the managing team without a law degree, and the only member with a law enforcement background.

- ABC's Ben Siegel

4:40 p.m. Senate rejects Schumer amendment calling for a subpoena for White House witnesses and documents

On a party line vote, 53-47, the Senate votes to put aside -- or kill -- Schumer's amendment to subpoena witnesses and documents from the White House.

Schumer proposes a new amendment to subpoena documents from the State Department related to calls between President Trump and Ukrainian President Zelenskiy.

There will be another two hours of debate on that amendment. McConnell says he will move to table that amendment as well.

4:14 p.m. Trump's lawyers argue all the Democrats's subpoenas have been invalid

Patrick Philbin, one of the lawyers on President Trump's defense team, pushes back on the Democrats' argument that the White House refused to cooperate with the inquiry.

He says the White House did respond to subpoena requests with a letter laying out why it saw the subpoenas were invalid - primarily that the House had not voted to authorize an official impeachment inquiry.

"All of those subpoenas were invalid," he says.

"And that was explained to the House, to manager Schiff and the other chairman of the committees at the time in that October 18th letter. Did the House take any steps to remedy that? Did they try to dispute that? Did they go to court? Did they do anything to resolve that problem? No."

After Philbin finishes, Schiff speaks again.

"Let's get this trial started, shall we?" Schiff says in response to the president's lawyers' claim that Democrats are pushing for more evidence because the House's case isn't strong enough.

"We are ready to present our case. We are ready to call our witnesses. The question is will you let us?" he asks.

As arguments conclude, McConnell makes a motion to put Schumer's amendment aside.

3:42 p.m. Former GOP Sen. Jeff Flake watches from Senate Gallery

Former Sen. Jeff Flake is in the chamber. He is seated in the upper level that is reserved for staff and guests. He looked over to the press area where reporters are seated and smiled.

The former senator and fierce Trump critic announced in 2017 that he would not seek reelection.

Flake notably has said that if the Senate held a secret ballot to remove Trump from office, more than 30 Republicans would vote to oust him.

3:34 p.m. House manager Zoe Lofgren says documents Democrats want subpoenaed would reveal 'the truth'

House manager Zoe Lofgren argues Schumer's amendment to subpoena key evidence from the White House would circumvent President Trump's efforts to block the House impeachment investigation by refusing to release documents or blocking officials from cooperating.

She says evidence released through Freedom of Information Act requests and messages from Ruddy Giuliani associate Lev Parnas made public after the House impeachment vote show that the White House documents could further implicate the president in wrongdoing concerning the withheld aid to Ukraine.

"The documents include records of the people who may have objected to this scheme, such as Ambassador (John) Bolton. This is an important impeachment case against the president. The most important documents are going to be at the White House. The documents Senator Schumer's amendment targets would provide clarity and context about president Trump’s scheme," Lofgren says.

"We don't know with certainty what the documents will say. We simply want the truth ... whatever that truth may be. So, so do the American people. They want to know the truth. And so should everybody in this chamber regardless of our party affiliation," she adds.

Lofgren points out that multiple witnesses in the House investigation testified they took detailed, handwritten notes around relevant events like the July 25 call between Trump and Ukrainian President Zelenskiy.

She says documents like those notes would provide a first-hand look at how Trump's behavior was perceived by those around him at the time.

3:26 p.m. Schiff argues the president's lawyers didn't even mention the rules resolution

After the break, Schiff pushes back on accusations from the president's lawyers that the House impeachment proceedings were unfair and that Republicans and representatives of the president weren't allowed to participate. He says it is "just plain wrong" to say Republicans weren't allowed in the depositions with witnesses or that the president wasn't allowed to send a representative to Judiciary Committee proceedings.

"I’m not going to suggest to you they are being deliberately misleading here, but it is just plain wrong. You have also heard my friends at the other table make attacks on me and chairman Nadler. You will hear more of that. I am not going to do them the dignity of responding to them, but I will say this. They make a very important point, although it's not the point I think they're trying to make," Schiff said.

"When you hear them attack the House managers, what you are really hearing is “we don't want to talk about the president's guilt. We don't want to talk about the McConnell resolution and how patently unfair it is.”

2:55 p.m. Inside the Senate chamber, senators taking notes, exchanging messages

As the Senate took a break, ABC's Mariam Khan reports senators, for the most part, were sitting quietly at their desks while Cipollone, Sekulow, and Schiff took turns speaking.

Senators seem to be paying close attention, maintaining eye contact with the speakers, and taking notes.

As Schiff spoke about the charges against the president, Trump’s key allies - GOP Sens. Lindsey Graham, David Perdue, Jim Risch, James Inhofe, and several others, stared stoically ahead.

Moderate GOP Sens. Susan Collins and Lisa Murkowski -- who are seated next to each other -- are taking copious amounts of notes, their faces expressionless.

While Schiff was speaking, Graham started to look a little bored, shifting in his seat constantly. While senators cannot speak to one another during the proceedings, he scribbled out a note on his legal notepad and shared it with his seat mate, Sen. John Barrasso.

Barrasso read the note, exchanged a knowing look with Graham and the two quietly chuckled.

When Schiff went on about the need for witnesses, Graham appeared to smirk.

When Schiff played a video of Trump saying he wanted to hear from witnesses - Minority Leader Schumer began to grin widely. He looked pleased.

Meanwhile, senators are still getting messages from the outside world. Aides are discreetly walking on to the floor to hand deliver paper messages to senators. Senate pages are walking around filling up water glasses.

2:39 p.m. President Trump's lawyers argue the Democrats failed to pursue their case in the courts

President Trump's personal attorney Jay Sekulow begins his argument by slamming the process in the House impeachment inquiry.

"And what we just heard from manager Schiff, courts have no role, privileges don't apply, what happened in the past we should just ignore. In fact, manager Schiff just said try to summarize my colleagues defense of the president," Sekulow says.

"He said not in those words of course, which is not the first time Mr. Schiff has put words into transcripts that did not exist. Mr. Schiff also talked about a trifecta," Sekulow says.

"I'll give you a trifecta. During the proceedings that took place before the Judiciary Committee, the president was denied the right to cross-examine witnesses. The president was denied the right to access evidence. And the president was denied the right to have counsel present at hearings. This is a trifecta that violates the Constitution of the United States. Mr. Schiff did say the courts really don't have a role in this. Executive privilege, why would that matter? It matters because it is based on the Constitution of the United States," Sekulow continues.

The president and his counsel could not participate in person during the depositions that House Intelligence, Judiciary and Oversight committees held but once the hearings moved to the House Judiciary Committee, the White House and the president chose not to participate even though they were invited to present a defense.

Pat Cipollone also says that Schiff was keeping Republicans out of the impeachment depositions. That is not true. Republicans on the committees mentioned participated in the depositions.

Sekulow argues that the only reason we are here is because Democrats want the president removed from office.

"What are we dealing with here? Why are we here? Are we here because of a phone call? Or are we before a great body because, since the president was sworn into office, there was a desire to see him removed."

He says that House Speaker Nancy Pelosi expressed her impatience and contempt for the proceedings and waiting for the courts to rule when she said "we cannot be at the mercy of the courts."

"That is why we have courts ... to determine constitutional issues of this magnitude," he said, although it should be noted that the administration has argued that the courts should not have a role here," he says.

-ABC's Katherine Faulders

2:13 p.m. GOP's Collins pressed to have arguments take place over 3 -- not 2 -- days

ABC's Trish Turner on Capitol Hill reports aides to moderate GOP Sen. Susan Collins say she and others raised concerns about trying to fit the 24 hours of opening statements in two days under the proposed rules and the admission of the House transcript of the evidence into the Senate record.

Her position has been that the trial should follow the Clinton model as much as possible, the aides say. She thinks these changes are a significant improvement, they say.

Later, during a break, a Republican senator - who asked not to be quoted - said the discussion of the tweaks to McConnell resolution was the topic of discussion at the GOP lunch today.

Some of the key senators, like Collins, “were clearly concerned about the topics around which changes were made," this senator said, reports ABC's Trish Turner.

”It was clear there was quite a bit of concern,” so it was changed, the senator said.

Sen. Ron Johnson said, “There was pretty strong feeling which is why it got changed,” saying the concern extended even beyond moderate senators. Republicans wanted to take an argument away from Schumer, he said. "We are not trying to hide testimony in the wee hours of the morning.”

2:08 p.m. Trump tweets from Switzerland

President Trump appears to be monitoring the Senate trial from his trip to Davos, Switzerland, to attend the World Economic Forum, reports ABC's Elizabeth Thomas.

A few minutes after he left a dinner with Global Chief Executive Officers, the last scheduled event of the day in Davos, Trump tweeted, "READ THE TRANSCRIPTS!" -- one of his favorite defenses, as he has often said before, referring to his calls with Ukraine's president -- calls which he calls "perfect."

1:34 p.m. Schiff says Trump is arguing there is nothing Congress can do about his conduct

House Intelligence Chairman Adam Schiff makes his first remarks in Tuesday's session, speaking on behalf of the House impeachment managers against McConnell's resolution.

He says Trump is arguing that there is nothing Congress can do about the behavior in question in the trial and the trial won't be fair if both sides are blocked from introducing new evidence.

"If a president can obstruct his own investigation, if he can effectively nullify a power, the Constitution gives solely to Congress and indeed the ultimate power, the ultimate power the Constitution gives to prevent presidential misconduct, then the president places himself beyond accountability, above the law," Schiff says.

"It makes him a monarch, the very evil which against our Constitution and the balance of powers the Constitution was laid out to guard against," he says.

Schiff continues to focus on the ability for the Senate to immediately hear from witnesses and receive additional documents before continuing with the trial.

“If the Senate votes to deprive itself of witnesses and documents the opening statements will be the end of the trial,” Schiff says.

Earlier on the Senate floor, McConnell said votes on subpoenas and witnesses should not happen until later in the trial, as outlined in the procedural resolution his office announced Monday. Most Americans, Schiff said, don’t believe there will be a fair trial and that Trump will be acquitted.

“Let’s prove them wrong! How? By convicting the president? No.” Schiff says. “By letting the House prove its case."

Schiff makes the case for additional evidence and witnesses in the Senate trial, with the help of the president's own words.

While speaking on the Senate floor, Schiff plays several clips of President Trump. The first shows Trump saying he wants witnesses, and another featuring the President saying Article II of the Constitution gives him the right to do "whatever I want."

"The innocent do not act this way," Schiff says.

This trial, he added, should not "reward" the president's obstruction by letting him determine what evidence is seen by the Senate.

He also pushed back on the criticism that the House had not exhausted its legal efforts in court to obtain access to witnesses and evidence.

Continuing to mount a legal case, Schiff argues, would encourage Trump to "endlessly litigate the matter in court on every judgment," essentially filibustering the impeachment process.

Schiff spoke after White House counsel Pat Cipollone spoke briefly on behalf of President Trump, in support of the rules and calling on the Senate to acquit the president as soon as possible.

1:20 p.m. Senate considers rules resolution that now calls for 24 hours of arguments over 3 days

With Chief Justice John Roberts presiding, the Senate begins considering the rules resolution proposed by McConnell that Democrats strongly object to as unfair.

The trial resumed at 1:17 p.m. after being scheduled to resume at 1 p.m.

In a major change, the proposed rules would now allow each side to make their case in a total of 24 hours over three -- not two -- days.

It also means the whole trial will likely take longer.

McConnell's team is expected to confirm that evidence from the House inquiry will now be admitted but not new evidence obtained since the House vote to impeach the president on Dec. 18.

Someone can OBJECT to that evidence being admitted, according to the proposed change.

12:35 p.m. McConnell says 'finally, some fairness' in opening remarks

Majority Leader McConnell begins his opening remarks -- before the formal start of the trial at 1 p.m. -- by saying, "finally, some fairness."

"This is the fair road map for out trial," he says of the proposed rules resolution he will soon formally introduce, saying it will bring the "clarity and fairness that everyone deserves."

Minority Leader Schumer calls McConnell's rules "completely partisan" and "designed by President Trump and for President Trump," adding they would mean "a rushed trial with little evidence in the dark of night."

Schumer says the McConnell rules are "nothing like the Clinton rules," saying that includes allowing a motion to dismiss the case to be made at any time.

As the senators argue, Chief Justice John Roberts, who will preside over the Senate trial, arrives on Capitol Hill.

12:25 p.m. Key GOP senators say they're on board with McConnell's proposed rules

Heading in their weekly closed-door GOP lunch, key senators Mitt Romney of Utah and Lisa Murkowski of Alaska say they’re on board with the McConnell's rules resolution, both indicating that it looks the same to them as the Clinton trial rules resolution.

Romney calls the difference between the Trump trial and Clinton resolutions “insignificant,” while Democrats have said there are major differences, accusing Republicans of using the rules to engineer a "cover-up."

“You’ll get what you need in eight-hour blocks or 12-hour blocks,” Romney says, referring to the length of each of the two days Democrats would have to present their case.

Murkowski echoes Romney, saying,“It’s the same 24 hours (as in Clinton), so what’s the difference if it’s eight hours or 12?”

Earlier, in a statement, Romney says, "If attempts are made to vote on witnesses prior to opening arguments, I would oppose those efforts."

-- ABC's Trish Turner and Devin Dwyer

11:31 a.m. Schumer says McConnell's proposed rules will force debate into the 'dead of night'

Ahead of the Senate trial, Minority Leader Chuck Schumer sharply criticizes the procedural rules outlined by McConnell Monday night.

Schumer takes issue with provisions he says would force debate into “the dead of night” and warns GOP moderate senators he will force an initial vote on whether to allow senators to review documents and question witnesses.

“Right off the bat, Republican senators will face a choice about getting the facts or joining leader McConnell and President Trump in trying to cover them up,” Schumer tells reporters.

“A trial with no evidence is not a trial at all. It’s a cover-up,” Schumer says.

“This is a historic moment,” Schumer adds. “The eyes of American are watching. Republican senators must rise to the occasion.”

When asked if he plans to force votes to oppose McConnell’s decision to split the 24 hours designated for opening arguments over two days, Schumer says “wait and see.”

Schumer says he will ask that White House documents be subpeonaed. including phone records between Trump and Ukraine's president, and other call records between administration officials about the military aid meant for Ukraine that Trump directed be withheld.

-- ABC's Mariam Khan

10:15 a.m. House managers complain about proposed trial rules

About three hours before they will appear on the Senate floor, House impeachment managers, led by House Intelligence Chairman Adam Schiff, hold a news conference to complain about McConnell's proposed rules, which would give them 24 hours over just two days or present their case, possibly meaning their arguments going past midnight.

"This is a process where you do not want the American people to see the evidence," Schiff says.

"We could see why this resolution was kept from us and the American people,” he says, calling it “nothing like” the Clinton resolution in terms of both witnesses and documents.

“It does not prescribe a process for a fair trial and the American trial desperately want to believe that the Senate ... will give the president a fair trial.”

Without documents, Schiff said, you can’t determine which witnesses to call and what to ask them.

He was joined by the full managing team.

He also said McConnell is “compressing the time of the trial,” citing the extended 12-hour days for arguments.

Schiff says managers will appeal to the senators today to “live up to the oath that they have taken.”

Rep. Jerry Nadler, the House Judiciary Committee chairman, who along with Schiff, will take the lead for the Democrats. Nadler said "there is no other conceivable reason the deny witnesses."

Nadler adds that all the Senate is doing is to “debate whether there will be a cover up,” accusing Republicans of “being afraid of what the witnesses will say.”

Schiff wouldn’t say if the House would use all 24 hours for their arguments and a full 12 hours each day but said that should be up to the House, and not the Senate in the trial rules.

-- ABC's Benjamin Siegel

9:19 a.m. House managers claim "ethical questions" about White House counsel Cipollone

House managers send a letter to a member of Trump’s legal team Tuesday morning stating that he was a “material witness” to the impeachment charges brought by the House. The managers, led by Schiff, claim there are “serious concerns and ethical questions” surrounding White House counsel Pat Cipollene’s role as Trump’s top impeachment lawyer.

“You must disclose all facts and information as to which you have first-hand knowledge that will be at issue in connection with evidence you present or arguments you make in your role as the President’s legal advocate so that the Senate and Chief Justice can be apprised of any potential ethical issues, conflicts, or biases,” the House managers write in a letter to Cipollone.

ABC News reported Friday that Cipollone would continue to lead the president’s defense through the impeachment trial along with the president's personal lawyer, Jay Sekulow.

They’re joined on Trump's defense team by former independent counsel lawyers Ken Starr and Robert Ray who were both involved in investigating and prosecuting the impeachment case against President Bill Clinton.

-- ABC's John Parkinson

For a president who likes a good show and seems to thrive on chaos, the opening of his impeachment trial Tuesday could give him exactly that.

Sources on Capitol Hill expect the first full day of the trial to be something of a political food fight. At the heart of that debate is whether or not to call witnesses who Democrats claim have first-hand knowledge of the president's alleged pressure campaign against Ukraine.

Rather than the staid proceedings of Bill Clinton's impeachment trial in 1999 -- which followed a close script known to the public, with opening arguments by the House impeachment managers -- the choreography of President Donald Trump's trial is something of a question mark that could see the chamber, known for its decorum and heady debate, run entirely off script, if not off the rails.

Ahead of Tuesday's trial, sources close to the president's legal team argued the articles of impeachment against Trump are "deficient on their face" because they fail to state any violation of law.

In the 110-page trial brief, lawyers for the president rejected the articles as a "brazenly political act" and argued that even if the president did raise the issue of the Bidens and/or Burisma in the course of engaging with Ukraine, there would be nothing wrong with that so long as the president was seeking to advance the public interest.

"Importantly, even under House Democrats' theory, mentioning the matter to President Zelenskyy would have been entirely justified as long as there was a basis to think that would advance the public interest. To defend merely asking a question, the President would not have to show that Vice President Biden (or his son) actually committed any wrongdoing," the brief argues.

For now, much of what will happen Tuesday hinges on how long this political slugfest continues. A senior administration official predicted it is "highly unlikely" opening arguments happen Tuesday, and that could complicate the push by GOP leaders and the White House to compress the schedule.

However, the White House has said it's "extraordinarily unlikely" the trial goes beyond two weeks.

Once Chief Justice John Roberts gavels the trial to order, and the opening prayer is given by Senate Chaplain Barry Black and impeachment proclamation by Sergeant at Arms Michael Stenger, Senate Majority Leader Mitch McConnell is expected to make a motion to take up his majority-only resolution that lays out the guidelines for the first phase of the trial.

The McConnell measure, released Monday night, condenses opening arguments by the managers and Trump lawyers to 24 hours each over two days per side, followed by up to 16 hours of questioning, via written special submissions by senators.

Democrats say a setup involving 12-hour days amounts to GOP efforts to "conceal" the president's alleged misconduct by conducting the trial in the "dead of night" when the American public is less likely to be paying attention.

On the crucial issue of whether or not to call witnesses, senators will vote up or down -- after the questioning period -- immediately following a four-hour period of debate on the issue. Key GOP senators, like Susan Collins of Maine and Utah's Mitt Romney, who have expressed interest in subpoenaing certain witnesses, insisted that this language be included.

"If the Senate votes no at that point, no party or Senator will be permitted to move to subpoena any witness or documents. If the Senate votes yes, both sides will be free to make motions to subpoena witnesses, and the Senate can debate and vote on them," according to a senior Senate GOP leadership aide.

Democrats were riled up by the GOP leader's exclusion of evidence not in the record at the time of the Dec. 18 House impeachment vote. It appears that any evidence related to Lev Parnas, a key associate of Trump personal attorney Rudy Giuliani, would not be permitted.

Parnas has been turning over evidence to congressional investigators that he argues is pertinent to their impeachment investigation. Democrats, who have been releasing the evidence publicly, argue that Republicans saying no new evidence should be included is "completely out of sync with how trials are done" and say any evidence that is in the public record should be considered.

"Impeachment rules do not automatically admit evidence from the House into the Senate trial," said a senior Senate GOP leadership aide. This is an important fact specific to this trial because the White House was denied due process throughout the 12 weeks of partisan House proceedings."

Democrats are expected to try to amend McConnell's trial rules with a request for witnesses and documents, according to sources familiar with their plans. But because of impeachment rules, no senator is allowed to debate anything in public.

That leaves the debate before cameras to both the House managers and the newly minted Trump legal team. Each side would likely get up to an hour to speak.

It will be the first time the public will see both sets of opponents on the Senate floor, seated at tables specially arranged for the occasion.

"We are going to demand votes -- yes or no, up or down -- on the four witnesses we've requested and on the three sets of documents we've requested. ... Make no mistake about it, we will force votes on witnesses and documents," Sen. Democratic Leader Chuck Schumer, D-N.Y., said in a press conference Sunday evening.

"It's going to be total chaos. No one knows what they're doing," said one former Senate aide with experience in impeachment trials.

McConnell's resolution is expected to include time for a motion to call witnesses after senators have had a chance to ask their questions of both sides, Sen. John Cornyn, R-Texas, confirmed.

This was important to middle-of-the-road GOP senators like Susan Collins of Maine and Alaska's Lisa Murkowski, as well as Romney. Collins signaled in a statement Thursday night that she is "likely" to support calling witnesses.