Even on Christmas, impeachment was on President Donald Trump's mind.

Trump spent at least part of his holiday and Thursday walloping Democratic House Speaker Nancy Pelosi with criticism over the latest moves in Congress' impeachment proceedings.

"Why should Crazy Nancy Pelosi, just because she has a slight majority in the House, be allowed to Impeach the President of the United States?" Trump said in a two-part tweet sent late Wednesday, ahead of a flurry of angry tweets Thursday morning.

He pointed to the total lack of Republican support for impeachment and claimed the process in the House was "very unfair."

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Trump also appeared to reverse his position on whether a Senate trial should even be allowed to proceed.

He sent a tweet quoting Bradley Blakeman, a Fox opinion writer and former staffer to President George W. Bush, advocating for Senate Republicans to dismiss the charges against Trump, bypassing a trial.

Trump TWEET Blakeman

That stance contradicts what Trump tweeted a week earlier, when he claimed that Democrats secretly "want out" of the impeachment process.

"I want an immediate trial!" Trump said in the Dec. 19 tweet.

Trump TWEET

The White House did not immediately tell CNBC if Trump's position on a Senate trial has changed.

Trump was impeached in the Democratic-led House earlier in December on charges of abuse of power and obstruction of Congress. But Pelosi has not yet sent the articles over to the Senate for an impeachment trial, amid concerns from Democrats about Senate Majority Leader Mitch McConnell's recent assertion that he is working in "total coordination" with the White House.

Republicans hold a 53-47 majority in the Senate. Since conviction and removal requires a two-thirds majority, most see Trump's acquittal as the most likely outcome from a trial.

McConnell, R-Ky., and Senate Minority Leader Chuck Schumer, D-N.Y., have met to try to hash out the rules for a Senate trial, but little progress appears to have been made.

Schumer has asked for the trial to include witnesses, including former national security advisor John Bolton and acting White House chief of staff Mick Mulvaney, who avoided testifying during the House impeachment inquiry.

McConnell rejected that request, saying in an Fox News interview Monday that the Senate's proceedings should mirror former President Bill Clinton's impeachment trial in the 1990s.

That trial involved a period for opening statements, followed by a written question period and a decision to allow witnesses to be questioned behind closed doors and allow video of their depositions to be played at the trial.

No Republican senators have said they will vote to convict Trump. But Sen. Lisa Murkowski of Alaska said in an interview that aired Tuesday that she was "disturbed" by McConnell's remarks.

"To me it means that we have to take that step back from being hand-in-glove with the defense," Murkowski told Alaska-based NBC news affiliate KTUU-TV. "I heard what leader McConnell had said. I happened to think that has further confused the process."

Murkowski is widely viewed as a moderate who is willing to voice dissent with Trump in a party that has largely become wedded to him. She says she remains undecided in how she will vote in the impeachment proceedings.

It's possible that new articles of impeachment could be drafted by the House, according to a court filing Monday from lawyers for the House Judiciary Committee.

The articles of impeachment are related to Trump's efforts to have Ukraine President Volodymyr Zelenskiy announce investigations of former Vice President Joe Biden and his son and a debunked conspiracy that Ukraine, not Russia, interfered in the 2016 presidential election.

Trump allegedly withheld hundreds of millions of dollars in congressionally approved military aid to Ukraine while he was pushing for the probes into his political rivals. His administration refused to comply with congressional Democrats' impeachment inquiry and has pressured numerous government witnesses not to cooperate.

While it's unclear how much leverage Democrats gain from Pelosi's decision to withhold the articles, her delay appears to be drawing Trump's ire.

"The Radical Left, Do Nothing Democrats said they wanted to RUSH everything through to the Senate because 'President Trump is a threat to National Security' (they are vicious, will say anything!)," Trump wrote in one of his tweets Thursday morning. "But now they don't want to go fast anymore, they want to go very slowly. Liars!"

Trump TWEET 2

And Trump continued to slam Pelosi as the morning progressed.

"Nancy Pelosi's District in California has rapidly become one of the worst anywhere in the U.S. when it come to the homeless & crime. It has gotten so bad, so fast - she has lost total control and, along with her equally incompetent governor, Gavin Newsom, it is a very sad sight!" he tweeted.

A representative for Pelosi didn't immediately respond to a request for comment.