WASHINGTON >> Republican opposition to impeaching President Donald Trump began crumbling at the party’s upper echelons today as the No. 3 House GOP leader said she would vote to impeach Trump.

“There has never been a greater betrayal by a President of the United States of his office and his oath to the Constitution,” Rep. Liz Cheney, R-Wyo., said in a statement that, while not unexpected, shook Congress as lawmakers prepared for a Wednesday House vote. With Democrats commanding that chamber, a vote impeaching Trump for an unprecedented second time seemed certain.

Michigan Rep. Fred Upton became the fourth Republican tonight to back the impeachment of President Donald Trump.

More ominously for a president clinging to his final week in office, The New York Times reported that influential Senate Majority Leader Mitch McConnell thinks Trump committed an impeachable offense and is glad Democrats are moving against him.

Citing unidentified people familiar with the influential Kentucky Republican’s thinking, the Times reported McConnell believes moving against Trump will help the GOP forge a future independent of the divisive, chaotic president.

McConnell thinks Trump’s behavior before last week’s assault on the Capitol by fuming Trump supporters cost Republicans their Senate majority in two Georgia runoff elections, the newspaper reported. That’s a sentiment shared by many Republicans about Trump, who rather than focusing on bolstering Georgia’s two sitting GOP senators spent the last weeks of their campaign reciting his false narrative that his own reelection was ruined by Democratic election fraud.

McConnell is said to be angry at the president over the insurrection at the Capitol and the twin defeats in Georgia that cost the party its Senate majority, according to a Republican granted anonymity to discuss the situation.

Cheney, daughter of former Vice President Dick Cheney, has run afoul of Trump and far-right Republicans over the years on issues like wearing a facemask and withdrawing troops from Syria. She’s respected by mainstream conservatives and is one of the GOP’s few House female stars.

“Good for her for honoring her oath of office,” House Speaker Nancy Pelosi, D-Calif., told reporters when asked about Cheney’s decision. “Would that more Republicans would honor their oaths of office.”

Lawmakers’ oath includes a vow to defend the Constitution “against all enemies, foreign and domestic.”

Reps. Adam Kinzinger, R-Ill., an Air Force veteran, and John Katko, R-N.Y., a former federal prosecutor, became the first rank-and-file GOP lawmakers to say they would vote to impeach Trump. Later joining the GOP faction was Rep. Fred Upton, R-Mich.

The House will vote on an impeachment article charging Trump with incitement of insurrection over his goading of a pro-Trump crowd that poured past police lines into the Capitol last Wednesday, disrupting lawmakers’ ceremonial counting of the electoral votes that sealed Trump’s defeat, leaving five dead and widespread damage.

“There is no doubt in my mind that the President of the United States broke his oath of office and incited this insurrection,” Kinzinger said in a statement about Trump, whom he’s repeatedly criticized over the years.

In a statement, Upton said: “Congress must hold President Trump to account and send a clear message that our country cannot and will not tolerate any effort by any President to impede the peaceful transfer of power from one President to the next.”

“To allow the president of the United States to incite this attack without consequence is a direct threat to the future of our democracy,” Katko said in a statement. “For that reason, I cannot sit by without taking action” and backing impeachment.

In remarks to his supporters outside the White House before they streamed to the Capitol, Trump told them “this is the time for strength,” adding, “We got to get rid of the weak Congress people,” describing them as “the Liz Cheneys of the world.”

Republicans have said they expected perhaps 10 House GOP lawmakers to break ranks and vote with Democrats to impeach Trump, and a clear majority of Republicans seem likely to stand by him.

But Trump may not have helped himself today. In his first public appearance since the attack on the Capitol, he took no responsibility for his role in egging on his supporters and added falsely, “People thought that what I said was totally appropriate.”

House Minority Leader Kevin McCarthy, R-Calif., has told his colleagues that he believes impeaching Trump would be wrong but has not ruled out censuring him or taking other steps. House GOP leaders say they won’t press their colleagues on how they will vote Wednesday.

In its story, the Times did not say how McConnell would vote in a Senate trial to convict Trump. Such a finding would usually result in a president’s removal from office, but in this case it seems unlikely a trial could be held and concluded before Jan. 20, when Democrat Joe Biden will be inaugurated to replace him.

McConnell has been the engine that has driven Trump’s Supreme Court appointees and scores of other federal judicial nominees through the chamber. While seldom criticizing Trump, he often resorts to silence when pressed by reporters on some of Trump’s more outrageous statements and their relationship has never seemed warm.

One White House official said McConnell and Trump last spoke in in mid-December.