Sen. Lamar Alexander, R-Tenn., announced late Thursday night that he would not support additional witnesses in President Trump's "shallow, hurried and wholly partisan" Senate impeachment trial, seemingly ending Democrats' hopes of hearing testimony from former national security adviser John Bolton and paving the way for the president's imminent acquittal as soon as Friday night.

"If this shallow, hurried and wholly partisan impeachment were to succeed, it would rip the country apart, pouring gasoline on the fire of cultural divisions that already exist," Alexander said. "It would create the weapon of perpetual impeachment to be used against future presidents whenever the House of Representatives is of a different political party."

He added: “The framers believed that there should never, ever be a partisan impeachment. That is why the Constitution requires a 2/3 vote of the Senate for conviction. Yet not one House Republican voted for these articles."

On Tuesday, Trump is set to address Congress for the annual State of the Union address, which is increasingly likely to resemble a victory lap following months of quixotic Democratic calls for the president's removal from office.

However, overnight, multiple congressional sources told Fox News that Senate Minority Leader Chuck Schumer, D-N.Y., could seek to have the trial spill over into next week -- past the State of the Union address and the Iowa caucuses -- by introducing a series of motions and calling for more debate.

“The Senate can only move as fast as its slowest member," one source. Asked when the trial would end, another replied, “when everyone is exhausted.”

On Friday, Sen. John Barrasso, R-Wyoming, told Fox News the Democrats "could throw a few Hail Marys” to drag the proceedings out, but it wouldn't change the outcome.

A lengthier trial could help presidential candidate Joe Biden, as two of his Democratic rivals, Sens. Amy Klobuchar and Elizabeth Warren, would be tied up in the Senate before and even during voting in the critical, first-in-the-nation caucus.

Fox News is told some of the new last-minute push could be designed to help Biden; some may be to avoid giving the president an acquittal just before State of the Union; and some may simply be that the Senate needs to give its members more say and debate.

Republicans have a 53-47 majority in the chamber, and can afford up to three defections when the Senate considers whether to call additional witnesses Friday -- a question that is considered by a simple majority vote. In the event of a 50-50 tie, by rule, the vote on witnesses would fail in the Senate. Chief Justice of the United States John Roberts is likely to abstain rather than assert his debatable power to cast a tie-breaking vote.

NADLER APPEARS TO STEAL PODIUM FROM SCHIFF IN VIRAL IMPEACHMENT MOMENT

The Senate will consider this precise question: “Shall it be in order to consider and debate under the impeachment rules any motion to subpoena witnesses or documents?”

Should the witness vote fail as expected on Friday evening, the Senate would likely then vote on either additional motions for debate, or even the articles of impeachment themselves. If the witness vote succeeds, it would likely extend the length of the trial significantly, and lead to extended debate over which witnesses to call.

When the final votes on the articles occurs, an extraordinarily unlikely two-thirds supermajority vote is needed to convict and remove Trump; otherwise he will be acquitted.

'Long night' ahead

As of midnight Friday, Sen. Susan Collins, R-Maine, has announced she wants to hear from a "limited" number of additional witnesses; Sen. Mitt Romney, R-Utah, has strongly signaled he wants to hear from Bolton; and Sen. Lisa Murkowski, R-Alaska, told Fox News late Thursday she was still weighing the issue and would decide in the morning. ("I’m gonna go back to my office and put some eyedrops in so I can keep reading. That’s gonna be my job," Murkowski told Fox News, adding that she anticipated a "long night.")

But Alexander, in his dramatic late-night statement that came at the close of the Senate's session Thursday, torpedoed Democrats' hopes that he would be the fourth Republican defector they need. Alexander flat-out dismissed Democrats' "obstruction of Congress" article of impeachment as "frivolous," citing the longstanding principle of executive privilege.

"There is no need to consider further the frivolous second article of impeachment that would remove the president for asserting his constitutional prerogative to protect confidential conversations with his close advisers," Alexander said.

At the same time, he said Democrats had easily proven their case on the "abuse of power" count that "the president asked Ukraine to investigate Joe Biden and his son, Hunter" and that "the president withheld United States aid, at least in part, to pressure Ukraine to investigate the Bidens."

However, Alexander, who is retiring, asserted that Trump's conduct did not justify the extraordinary remedy of his immediate removal by the Senate, especially in an election year.

"Let the people decide.” — U.S. Sen. Lamar Alexander, R-Tenn.

"I worked with other senators to make sure that we have the right to ask for more documents and witnesses, but there is no need for more evidence to prove something that has already been proven and that does not meet the United States Constitution’s high bar for an impeachable offense," Alexander said.

“There is no need for more evidence to prove that the president asked Ukraine to investigate Joe Biden and his son, Hunter; he said this on television on October 3, 2019, and during his July 25, 2019, telephone call with the president of Ukraine," he continued. "There is no need for more evidence to conclude that the president withheld United States aid, at least in part, to pressure Ukraine to investigate the Bidens; the House managers have proved this with what they call a ‘mountain of overwhelming evidence.’ There is no need to consider further the frivolous second article of impeachment that would remove the president for asserting his constitutional prerogative to protect confidential conversations with his close advisers.

“It was inappropriate for the president to ask a foreign leader to investigate his political opponent and to withhold United States aid to encourage that investigation," he continued. "When elected officials inappropriately interfere with such investigations, it undermines the principle of equal justice under the law. But the Constitution does not give the Senate the power to remove the president from office and ban him from this year’s ballot simply for actions that are inappropriate."

Indeed, Alexander said, “Our founding documents provide for duly elected presidents who serve with ‘the consent of the governed,’ not at the pleasure of the United States Congress. Let the people decide.”

“The question then is not whether the president did it, but whether the United States Senate or the American people should decide what to do about what he did," Alexander said. "I believe that the Constitution provides that the people should make that decision in the presidential election that begins in Iowa on Monday. The Senate has spent nine long days considering this ‘mountain’ of evidence, the arguments of the House managers and the president’s lawyers, their answers to senators’ questions and the House record. Even if the House charges were true, they do not meet the Constitution’s ‘treason, bribery, or other high crimes and misdemeanors’ standard for an impeachable offense."

The left reacts

Reaction from the left was immediate and emotional. Mara Gay, a member of The New York Times editorial board, lamented on MSNBC that the situation was "really a capstone in a, just, total collapse of faith in American institutions."

Gay went on to say that her father grew up in the Jim Crow-era South, and declared that Republicans' arguments were "quite familiar" and reminded her of that time.

"And you know, I have to say, as somebody who grew up with a father who grew up in the Jim Crow South, and in, uh, Jim Crow Detroit, a lot of what this has looked like from the Republican side, the kind of a maddening and farcical nature of this, the lack of good-faith argument, sounds very familiar to me. It's actually very scary."

PELOSI SUGGESTS TRUMP'S LAWYERS SHOULD BE DISBARRED

Anchor Brian Williams, who notably lied repeatedly in order to embellish his time in Iraq, then said that Gay spoke for a "metric ton" of the network's viewers.

The Senate impeachment trial question-and-answer phase wrapped up Thursday night after a total of 180 interrogatories, setting up the pivotal vote Friday on whether to subpoena additional witnesses and documents, or to hold a final vote on whether to impeach or acquit President Trump.

Dry January

Last December, Senate Majority Leader Mitch McConnell, R-Ky., published the Senate schedule for 2020. He only put 11 months on the calendar, completely leaving out January, because no one quite knew what was in store for the Senate with a possible impeachment trial. If the Senate wraps up the trial Friday night, McConnell will have correctly predicted how long it would take to acquit the president.

Meanwhile, as expected, Collins announced after the conclusion of questioning that she supports hearing from a "limited" number of additional witnesses.



"I believe hearing from certain witnesses would give each side the opportunity to more fully and fairly make their case, resolve any ambiguities, and provide additional clarity," Collins said. "Therefore, I will vote in support of the motion to allow witnesses and documents to be subpoenaed. ... If this motion passes, I believe that the most sensible way to proceed would be for the House Managers and the President’s attorneys to attempt to agree on a limited and equal number of witnesses for each side. If they can’t agree, then the Senate could choose the number of witnesses.”

Separately, though, Collins has signaled reluctance about Democrats' case: On Wednesday, she was seen shaking her head as Democrats attempted to explain why they felt non-criminal conduct like "abuse of power" should be impeachable.

GAME OVER': TRUMP DECLARES VICTORY AFTER BOLTON VIDEO EMERGES

Trump defense counsel Patrick Philbin said late Thursday that if Democrats want to "go down the road" of adding more witnesses, then Trump's team would push aggressively to learn more about the Ukraine whistleblower's contact with Democrats in the House prior to filing his complaint, as well as the whistleblower's own apparent partisan bias.

Additionally, Trump's defense team argued that Democrats contradicted themselves by saying their case was "overwhelming" and that Trump was guilty beyond "any doubt" -- even as they insist that they need to call more witnesses and see more evidence.

Momentum has been shifting away from a vote in favor of witnesses, ever since Trump tweeted a link Wednesday to an interview of Bolton in August 2019 where he discusses Ukraine policy. In the Radio Free Europe/Radio Liberty interview clip, Bolton makes no mention of any illicit quid pro quo, and acknowledges, as Republicans have claimed, that combating "corruption" in Ukraine was a "high priority" for the Trump administration.

Bolton also called Trump's communications with Ukrainian President Volodymyr Zelensky "warm and cordial," without mentioning any misconduct. It seemingly contradicted reported assertions in Bolton's forthcoming book alleging that Trump explicitly told him he wanted to tie military aid to Ukraine to an investigation into Joe and Hunter Biden.

Trump captioned the video: "GAME OVER!"

Dems' headscratchers

House impeachment manager Rep. Hakeem Jeffries, D-N.Y., and presidential contender Sen. Elizabeth Warren, D-Mass., raised eyebrows during the proceedings Thursday -- including from Chief Justice Roberts.

At one point Thursday afternoon, Jeffries argued that the Steele dossier -- written by a foreign ex-spy and dependent in part on Russian sources -- did not constitute improper foreign election interference because the Hillary Clinton campaign and Democratic National Committee (DNC) paid for the dossier, rather than receiving it at no cost.

His claim came in response to a question from Sen. Richard Burr, R-N.C., that was aimed at arguing how the Democrats wouldn't want to apply their standards to their own candidates.

"Hillary Clinton's campaign and [the] Democratic National Committee hired a retired foreign spy to work with Russian contacts to build a dossier of opposition research against their political opponent, Donald Trump. Under the House managers' standard, would the Steele dossier be considered foreign interference in the U.S. election, a violation of the law, and/or an impeachable offense?" Burr asked.

Jeffries then rose and declared, "The analogy is, uh, not applicable to the present situation because, first, to the extent that opposition research was obtained, it was opposition research that was purchased."

He then accused Republicans of avoiding facts and trying to distract from Trump's conduct.

Jeffries' response drew mockery online from a slew of commentators -- "Cut a check to Ukraine. We're done here," wrote one -- and an immediate rebuke in the chamber from Trump attorney Jay Sekulow.

"So, I guess you can buy -- this is what it sounds like -- you can buy foreign interference? You can purchase it? You can purchase their opposition research and I guess it's OK?" he asked.

WATCH THE FULL JEFFRIES MELTDOWN MOMENT HERE

One of the dossier's foreign sources was the former deputy foreign minister for Russia, Vyacheslav Trubnikov -- a known Russian intelligence officer. Much of the Steele dossier has been proved unsubstantiated, including the dossier's claims that the Trump campaign was paying hackers based out of a nonexistent Russian consulate in Miami or that ex-Trump lawyer Michael Cohen traveled to Prague to conspire with Russians. Former Special Counsel Robert Mueller also was unable to substantiate the dossier's claims that Page had received a large payment relating to the sale of a share of Rosneft, a Russian oil giant, or that a lurid blackmail tape involving the president existed.

Nevertheless, the FBI relied heavily on the dossier to obtain a secret surveillance warrant to monitor a former member of the Trump campaign, Carter Page. News of that warrant leaked, and together with the dossier's salacious accusations, fueled months of unfounded speculation that the Trump campaign had conspired with Russia.

GRASSLEY: US INFORMANT MAY HAVE RECEIVED TAXPAYER FUNDS FOR COUNTER-INTEL OP ON TRUMP CAMPAIGN

Separately, at the Senate impeachment trial Thursday, Warren posed a question that, by rule, was read aloud by Roberts -- and even Democrats in the chamber appeared visibly puzzled by the interrogatory.

"At a time when large majorities of Americans have lost faith in government, does the fact that the chief justice is presiding over an impeachment trial in which Republican senators have thus far refused to allow witnesses or evidence contribute to the loss of legitimacy of the chief justice, the Supreme Court and the Constitution?" Roberts read from the card handed to him by the clerk.

When he finished reading the question -- explicitly posed to the House impeachment managers -- Roberts pursed his lips and shot a chagrined look.

After a moment, Rep. Adam Schiff, D-Calif., the lead impeachment manager, appeared at the dais to answer the question -- standing mere feet in front of Roberts.

'COUP HAS STARTED,' UKRAINE WHISTLEBLOWER'S ATTORNEY PROMISED IN 2017, VOWING TO IMPEACH AND 'GET RID OF' TRUMP

Schiff appeared to try to distance himself from Warren's question, offering a short answer to the question before speaking at length about a tangential exchange.

"I would not say that it leads to a loss of confidence in the chief justice," Schiff said, adding that Roberts has thus far "presided admirably."

He then quickly pivoted to a criticism of President Trump and a conversation he had about the impeachment trial with Rep. Tom Malinowski, D-N.J.

Whistleblower showdown

Justice Roberts shut down a question Thursday from Sen. Rand Paul, R-Ky., that mentioned the name of the alleged Ukraine whistleblower, prompting Paul to storm out of the impeachment trial and hold an impromptu news conference to read the question anyway.

The clash came after the chief justice, who is presiding over the trial, similarly rebuffed Paul a day earlier. (Paul, according to reporter Niels Lesniewski, was apparently fuming afterward, shouting to a staffer: "I don't want to have to stand up to try and fight for recognition. ... If I have to fight for recognition, I will.")

JUSTICE ROBERTS BLOCKS SEN. PAUL FROM NAMING WHISTLEBLOWER, SOURCE SAYS – AND PAUL MAY FORCE THE ISSUE

“As you may have noticed, we had something slightly atypical downstairs. I asked a question and the question was refused,” Paul told reporters after exiting the Senate chamber and dashing upstairs to the Senate TV studio.

After seeing Paul’s question on a notecard, Roberts ruled against presenting it in the trial: "The presiding officer declines to read the question as submitted,” he said.

Paul asserted that Roberts' ruling was wrong because no one knows if the name of the person on his question card is the whistleblower.

“I think it was an incorrect finding," Paul said.

Paul wanted to ask whether Schiff, who chairs the House Intelligence Committee, and the White House counsel were aware that an intel committee staff member had a close relationship with the reported whistleblower when they were on the National Security Council together.

“How do you respond to reports that [the whistleblower] may have worked together to plot impeaching the president before there were formal House impeachment proceedings?” Paul said he wrote on the card.

He added that his question “makes no reference to anybody who may or may not be a whistleblower,” and that it was curious that Roberts apparently assumed the individual he named was, in fact, the whistleblower.

Schiff has made public inconsistent statements concerning the House Intelligence Committee's contacts with the whistleblower. He first denied that his panel had such contact, then reversed course and admitted that members of the committee had spoken to the whistleblower.

Paul's question reportedly included the names of two individuals. Fox News has not confirmed the whistleblower's name.

Federal law protects whistleblowers only from retaliation in the workplace and does not ensure their anonymity; Republicans have disputed whether this particular whistleblower would even qualify for those limited protections, saying his complaint concerns a policy dispute and does not allege criminal or civil wrongdoing by the president.

Eventually, Republicans were allowed to ask essentially the same question Paul proposed, except without the whistleblower's name in it. Schiff declined to respond, calling it a smear.

Specifically, Republicans asked Schiff, “Why did your committee hire Sean Misko the day after the phone call between President Trump and Zelensky?”

According to unconfirmed reports, Misko was overheard telling the alleged whistleblower, “We need to do everything we can to take out the president," at a National Security Council meeting.

It could be, Republicans have asserted, that the whistleblower coordinated his complaint with Schiff's panel for partisan reasons -- a disclosure that, if true, would likely undermine the credibility of the impeachment proceedings and possibly expose Schiff to his own "abuse of power" allegations. Thus far, the impeachment effort has arguably been elevated in importance from normal partisan bickering in part by the gravitas afforded to the supposedly well-meaning whistleblower at the center of the case.

SCHIFF, IN REVERSAL, ADMITS HE SHOULD HAVE BEEN CLEAR ABOUT HIS OWN CONTACT WITH THE WHISTLEBLOWER

Republicans have sought more information on the whistleblower ever since the intelligence community's internal watchdog found several indicators that the person might have a political bias.

Fox News has previously reported that the whistleblower is a registered Democrat and had a prior work history with a senior Democrat running for president. Additionally, the whistleblower faces an Intelligence Community Inspector General (ICIG) complaint for allegedly violating federal law by raising money ostensibly to pay for his legal fees, including money that could be coming from foreign sources.

The whistleblower's attorney, Mark Zaid, openly admitted in 2017 that a "coup" had started against the president from within the administration, and that CNN's coverage would play a "key role" in the effort.

On Wednesday, Schiff again denied knowing the identity of the whistleblower, while Republicans accused him of deliberately lying. Schiff repeatedly shut down GOP questions during the House impeachment proceedings concerning White House leaks -- even though doing so at one point seemingly demonstrated that Schiff likely knew the whistleblower's identity.

“Lieutenant Colonel [Alexander] Vindman, did you discuss the July 25 phone call [between Trump and Ukraine's president] with anyone outside the White House on July 25 or the 26 and if so, with whom?” Rep. Devin Nunes, R-Calif., asked last year.

GOP SEN ACCUSES DEM WITNESS OF CONSPIRING TO BRING DOWN TRUMP

“Yes. I did,” responded Vindman, who has also claimed not to know the whistleblower's identity. He said he had spoken to Deputy Assistant Secretary George Kent, but before he could mention the other person, Schiff intervened and urgently blocked the questioning.

“We need to protect the whistleblower," Schiff interjected. "Please stop. I want to make sure that there is no effort to out the whistleblower through these proceedings. If the witness has a good faith belief that this may reveal the identity of the whistleblower, that is not the purpose that we’re here for. I want to advise the witness accordingly.”

Dershowitz faces off with Toobin

Harvard Law Professor Alan Dershowitz, a member of Trump's defense team, wasn't in the Senate chamber Thursday due to family obligations. But he did post on Twitter and make a lengthy appearance on CNN, telling the network that it should stop mischaracterizing his arguments on impeachment.

The moment was somewhat personal for Dershowitz, as CNN's chief legal analyst Jeffrey Toobin is one of his former students at Harvard. Multiple media outlets, including CNN, misrepresented Dershowitz throughout the week as saying that presidents can do "anything" as long as they can argue it's in the "public interest." Additionally, several politicians, including Sen. Cory Booker, D-N.J., falsely claimed that Dershowitz argued Trump's conduct was "OK."

In fact, Dershowitz maintained that criminal or criminal-like conduct is impeachable, regardless of its motivation. And he did not endorse Trump's behavior. Instead, Dershowitz asserted the Senate should not be in the business of removing elected presidents based on nebulous and unconstitutional "abuse of power" or "obstruction of Congress" charges that the framers expressly rejected.

"I have never said that a president can do anything if he believes that his election is in the public interest to get reelected," Dershowitz told Toobin and CNN anchor Wolf Blitzer. "That's simply false. I started my speech in the Senate by saying I completely support the impeachment of [Richard] Nixon, who everything he did, he did because he wanted to get reelected. And clearly he thought his reelection was in the public interest."

He added: "I never said, never suggested -- and it was a total distortion, not a misunderstanding, distortion of my point -- that I think a president can do anything ... It's nonsense. And your network should never have said that."

"What's wrong with looking at whether a president has a corrupt intent in his actions?" Toobin responded. "I mean, that seems to be the heart that is the issue here."

"It's not, it's not," Dershowitz said. "The question is how you define corrupt, and my argument was there's a big difference between taking a bribe -- I gave an example right on the floor of the Senate. If the president said, 'I'm not giving you your money, I'm withholding the money unless you let me build a hotel and have my name on it or give me a million-dollar kickback.' That's corrupt. That's clear."

Dershowitz went on to say it would be a "dangerous" principle to say that a president can be impeached if he acts, in part, due to personal political motivation, because "it will allow impeachment of any president who look to his own reelectability as even a small factor."

To demonstrate that point in the Senate on Wednesday, Dershowitz made thinly veiled references to former President Barack Obama's refusal to send military aid to Ukraine, as well as his failed, unenforced "red line" warning for Syria not to use chemical weapons. Obama was also caught on a hot microphone promising Russia's president he would have "more flexibility" on missile defense issues after the 2012 election.

"Let's consider a hypothetical," Dershowitz said. "Let's assume that President Obama had been told by his advisers that it really is important to send lethal weapons to the Ukraine. But then he gets a call from his pollster and his political adviser, who says we know it's in the national interest to send lethal weapons to the Ukraine, but we're telling you that the left-wing of your party is really going to give you a hard time if you start selling lethal weapons and potentially get into a lethal war with Russia. Would anybody here suggest that is impeachable?"

WATCH: DERSHOWITZ TURNS TO HOUSE DEMS, UNLOADS CONSTITUTIONAL ARGUMENT IN DRAMATIC MOMENT AT IMPEACHMENT TRIAL

He continued: "Or let's assume President Obama said, 'I promise to bomb Syria if they had chemical weapons. But I'm now told by my pollster that bombing Syria would hurt my electoral chances.' Simply not impeachable at all."

Earlier in the day, also on CNN, Harvard Law School professor Nikolas Bowie disputed Dershowitz as to whether "maladministration" -- a term the framers rejected as a viable grounds for impeachment -- was essentially the same as "abuse of power," one of the Democrats' charges against Trump.

Bowie called Dershowitz's interpretation a "joke," in a slam that was especially notable because Dershowitz had cited Bowie's scholarship on the Senate floor.

Dershowitz was simply wrong, Bowie argued, that maladministration is synonymous with abuse of power. The former is equivalent to doing your best but turning in poor work product, he argued; the latter is fundamentally criminal, even if it's not defined anywhere in a statute.

What's ahead

The impeachment trial reconvenes at 1 p.m. ET Friday. The Senate will immediately go to up to four hours of arguments by the Democratic impeachment managers and the defense counsel. There could also be deliberation by senators, which might involve a closed session or even debate among the senators themselves on the floor.

Regardless, once that’s done, the Senate will debate a proposal to subpoena documents or witnesses. That could consume up to two hours on the floor – and will not unfold until the evening.

After that’s complete, the Senate will take what is termed the “gateway” vote as to whether or not to open the door to subpoenaing witnesses or documents.

If, contrary to expectations, senators vote to open up the gateway to witnesses or documents, a multitude of proposals could follow over several hours from McConnell and Senate Minority Leader Chuck Schumer, D-N.Y. These would likely be various slates of witness proposals. Democrats would like to get Republicans on the record opposing certain witnesses. Democrats would then try to boomerang that vote on vulnerable Republicans this fall and argue that McConnell tilted the playing field in the trial toward the president.

SOURCE TELL FOX NEWS: GOP DEVELOPS WITNESS 'PLAN B' POISON PILL PACAKGE, FLOATS CALLING HUNTER BIDEN, ADAM SCHIFF

If for some reason the Senate votes in favor of an individual witness, then the trial is far from done. The Senate trial rules require senators to depose the witness in private. That could come in days or weeks, but in the meantime, the trial on the floor would go dark. (However, the Senate could consider other business during this period. The Senate would eventually have to vote to summon a given witness to the floor.)

If the Senate rejects the gateway vote, the impeachment trial is likely on a glide path to conclusion. There could be additional debate after that; the Senate could consider a motion to dismiss the articles; or there could be final verdict votes on both articles of impeachment.

Schumer, D-N.Y., might extend the proceedings into next week through numerous motions for debate, Fox News was told by multiple sources overnight.

WHOOPS: BIDEN CAMPAIGN TOUTS UKRAINE ACTIVIST WHO CALLED HUNTER BIDEN'S ACTIONS 'VERY BAD'

It remains possible the Senate could take final votes on each article of impeachment -- there will be separate, distinct votes on abuse of power and obstruction of Congress -- late Friday evening, in the wee hours of Saturday morning or later in the day Saturday.

Several Democratic senators have privately signaled they want the trial to wrap up quickly -- partially out of exhaustion, but also because Sens. Amy Klobuchar and Elizabeth Warren urgently want to get back to Iowa to campaign ahead of next week's critical caucuses.

Fox News' Chad Pergram and Marisa Schultz contributed to this report.

Fox News' Chad Pergram, Mike Emanuel, Marisa Schultz and Charles Crietz contributed to this report.