A political "earthquake" is under way in America, with roughly 20 Republicans in the House of Representatives expected to vote to impeach President Donald Trump.
Three senior Republicans in the House - Liz Cheney, Adam Kinzinger and John Katko - have already broken ranks this morning, saying they will vote against the President tomorrow.
"The President of the United States summoned this mob, assembled the mob, and lit the flame of this attack," Cheney wrote in a stinging statement released this morning (NZT).
"Everything that followed was his doing. None of this would have happened without the President."
White House officials who spoke to both CNN and Fox News now expect as many as 20 or more Republicans to vote for impeachment.
Last time Trump was impeached, the vote had no support from Republicans.
Democratic Representative Adam Schiff described the developments as an "earthquake" in the Republican party.
"These things have a way of gathering momentum," Schiff told CNN. "I wouldn't be surprised now to see a considerable number of Republicans join in supporting the impeachment resolution."
Senate Majority Leader Mitch McConnell is reportedly pleased about plans to impeach Trump, believing it is the first step in "purging" the President from the party.
McConnell, previously a staunch ally of the President, has told associates he believes Trump has committed impeachable offences, The New York Times reports.
The Times is also reporting that House Minority Leader Kevin McCarthy, one of Trump's most steadfast allies in Congress, has asked other Republicans whether he should call on Trump to resign.
As reports of Republican defections emerged today, Vice President Mike Pence ruled out invoking the 25th Amendment to remove Trump from office.
In a letter to House Speaker Nancy Pelosi, Pence said the amendment should not be used "as a means of punishment or usurpation" – rather it should be reserved for cases of medical or mental incapacitation.
"Now with just eight days left in the President's term, you and Democratic Caucus are demanding that the Cabinet and I invoke the 25th Amendment. I do not believe that such a course of action is in the best interest of our Nation or consistent with our Constitution," Pence wrote.
As politicians debated the fate of the President, the Joint Chiefs of Staff - a group of the most senior uniformed leaders at the Pentagon - released a statement condemning the riot at the Capitol as a "direct assault" on Congress and the constitutional process.
The statement – issued to the entire US military – is extraordinary because the chiefs usually stay out of politics.
"As Service Members, we must embody the values and ideals of the Nation. We support and defend the Constitution. Any act to disrupt the Constitutional process is not only against our traditions, values, and oath; it is against the law," the statement said.
Trump faces a single charge - "incitement of insurrection" - in the impeachment resolution that the House will begin debating tomorrow, a week before Democrat Joe Biden is set to be inaugurated on January 20.
In his first public appearance since Thursday's unrest, Trump remained defiant, insisting he bore no responsibility for his supporters' actions.
"People thought that what I said was totally appropriate," Trump said today during a trip to Alamo, Texas, to tour a part of the US-Mexico border wall.