Sen. Tim Scott (R-S.C.), the lone African-American GOP senator, said he “wouldn’t use” the term but largely supported the president’s broader frustrations.

“This is the political version of a death row trial. The president is up in arms in anger about it,” said Scott, who met privately with Trump in 2017 after the president defended white supremacists rallying in Charlottesville. “He’s putting his political life on trial. His comments reflect it.”

Republicans had already been privately expressing frustration that Trump has been acting as a one-man war room in the impeachment fight, lashing out in Cabinet meetings and lobbing attacks from his Twitter account. But they were utterly unprepared for what was awaiting them on Tuesday morning.

“So some day, if a Democrat becomes President and the Republicans win the House, even by a tiny margin, they can impeach the President, without due process or fairness or any legal rights,” he wrote on Twitter. “All Republicans must remember what they are witnessing here - a lynching. But we will WIN!”

Trump’s latest controversy put Republicans in an uncomfortable, albeit familiar, spot: stand with the president or distance themselves from him.

Some of Trump’s top allies on Capitol Hill showed little interest in jumping on Trump’s latest grenade, but they also refused to slam him.

"That's not the language I would use," said House Minority Leader Kevin McCarthy (R-Calif.) at his weekly press conference. “I don't agree with that language, pretty simple."

“He could have used different language,” added House Minority Whip Steve Scalise (R-La.), while making clear that he agrees with Trump’s frustration over the process.

Senate Majority Leader Mitch McConnell (R-Ky.) also expressed his disapproval.

"Given the history of this in our country, I would not compare it to a lynching," he told reporters. "That was an unfortunate choice of words."

Other members of GOP leadership went further.

“Inappropriate. That’s not appropriate in any context,” said Senate Majority Whip John Thune (R-S.D.).

Democrats were harsher.

“You are comparing a constitutional process to the PREVALENT and SYSTEMATIC brutal torture of people in THIS COUNTRY that looked like me?” tweeted Rep. Karen Bass (D-Calif.), chairwoman of the Congressional Black Caucus.

But amid calls from Trump to "get tougher and fight" on his behalf in the impeachment fight, some Republicans are doing just that.

Sen. Lindsey Graham (R-S.C.) said the House’s actions amount to a “lynching in every sense” on Tuesday morning, throwing himself in with the president. Later in a gaggle with more than a dozen reporters, Graham called the process “literally a political lynching,” questioned the state of journalism and scolded them for asking about the racial connotations of Trump’s statement.

“It’s not just racial, my friend. I’m from South Carolina. I understand it very well. Here’s what you don’t get. Mob rule is what lynching is all about. You grab somebody because you don’t like them,” Graham said. “This is what happened to Kavanaugh: You’re guilty unless you can prove yourself innocent.”

Sen. Ted Cruz (R-Texas) acknowledged that the term carries carries "significant historical freight" but largely agreed with the president's complaints.

"The connotation the president is carrying forward is a political mob seeking an outcome regardless of facts. And that I think is an objectively true description of what is happening in the House right now," he said.

Still, the GOP has grown increasingly exasperated with Trump over the past month. The president abruptly withdrew troops from the border of Syria and announced — and then reversed — plans to host the G-7 summit at his own struggling Miami resort, in what appeared to be a clear instance of profiting from the presidency.

The lynching comments were just the latest headache for the GOP. Centrist Rep. Brian Fitzpatrick (R-Pa.) said in an interview that type of language “is not okay.”

And Rep. Adam Kinzinger (R-Ill.) called on Trump to delete the tweet.

“We can all disagree on the process, and argue merits. But never should we use terms like “lynching” here,” tweeted Kinzinger, who has been increasingly critical of Trump. “The painful scourge in our history has no comparison to politics, and @realDonaldTrump should retract this immediately. May God help us to return to a better way.”

But Republicans also acknowledge the president doesn’t typically retract or apologize for his behavior, and few expect it this time.

And even Republicans who have been critical of Trump appeared tired of having to respond to his latest controversial tweet.

Sen. Lisa Murkowski (R-Alaska), when told about the tweet, merely responded "that's disturbing," while Sen Mitt Romney (R-Utah), who has spoken out vehemently against Trump in recent weeks, declined to comment further.

"You know, I think I've said enough about the President's tweets, as of late," Romney said.

“It’s too late to take it down. It doesn’t matter,” said one GOP lawmaker, who was disappointed with Trump’s language.

Trump has frequently used the phrase “witch hunt” and other politically explosive language to undermine Democratic investigations and former special counsel Robert Mueller’s probe into Russian interference in the 2016 election.

But the invocation of “lynching” to characterize a process explicitly sanctioned by the Constitution marked a new, racially fraught show of malice by the president toward lawmakers’ drive to remove him from office.

“@realDonaldTrump and @LindseyGrahamSC this is a lynching,” tweeted Michael Steele, linking to a picture of an African American man being hung by noose from a tree.

Steele, the former chairman of the Republican National Committee, continued: “Trump this is not happening to you and it’s pathetic that you act like you’re such a victim; but it did happen to 147 black people in your state Lindsey. ‘A lynching in every sense’? You should know better.”

Several black Democratic lawmakers expressed similar indignation at Trump’s analogy.

“You think this impeachment is a LYNCHING? What the hell is wrong with you?” tweeted Rep. Bobby Rush (D-Ill.), a civil rights activist who co-founded the Illinois chapter of the Black Panther Party. “Do you know how many people who look like me have been lynched, since the inception of this country, by people who look like you. Delete this tweet.”

Quint Forgey contributed to this report.