Democratic members of Congress are pressing ahead with preparations for the second impeachment trial of former president Donald Trump, saying there is a “compelling” case for Trump to be convicted of inciting an insurrection and arguing that moving forward with a trial is imperative for the country’s healing.

Meanwhile, the fractures within the Republican Party were evident Sunday as GOP senators appeared split over whether it was constitutional to hold an impeachment trial for a president who had already left office. Sen. Mitt Romney (R-Utah), one of Trump’s most outspoken GOP critics, stopped short of saying he would vote to convict Trump, while Republican allies of the former president continued to argue that an impeachment trial should be abandoned for the sake of “unity.”

Members of the Republican National Committee also were in a heated debate over the weekend on how to respond to impeachment — and how fiercely to defend Trump, who maintains support among a majority of the 168 committee members, party officials and members said.

On Jan. 24, the day before an impeachment article was set to be sent to the Senate, lawmakers discussed the upcoming trial for former president Donald Trump. (The Washington Post)

House impeachment managers are planning to send an article of impeachment to the Senate on Monday, alleging “incitement of insurrection” after a pro-Trump mob stormed the U.S. Capitol on Jan. 6 in a violent riot that left a Capitol Police officer and four others dead. On Friday, Senate Majority Leader Charles E. Schumer (D-N.Y.) announced that the second impeachment trial will start Feb. 9 after reaching a deal with Minority Leader Mitch McConnell (R-Ky.) that will allow the Senate to focus on President Biden’s agenda and also for Trump to put together a defense.

When asked whether the trial’s two-week delay would cost Democrats the little Republican support they had for impeachment, Sen. Elizabeth Warren (D-Mass.) balked and said the events of Jan. 6 went far beyond the many other norms Trump had broken in office.

“I can’t imagine how Republican opposition to insurrection would fade over the space of a couple of weeks,” Warren said on CNN’s “Inside Politics” on Sunday. “We’re talking about a president who stood in front of a mob and told them to go to the Capitol and invade, told them to go to the Capitol and stop the lawful business of government so that he could try to stay in the White House. That is so fundamentally wrong. . . . We need accountability, accountability for Donald Trump and accountability for everyone who participated in that insurrection.”

Romney, who clashed frequently with Trump, said there was a “preponderance” of legal opinions that supported moving forward with a trial even though Trump’s term is finished. He said he hoped the impeachment process would be over quickly.

Romney did not say whether he would vote to convict Trump, but he did say “there’s no question” that the article prepared by the House suggests impeachable conduct. He said he wanted to hear the president’s defense before deciding.

“It is pretty clear that over the last year, there has been an effort to corrupt the election in the United States, and it was not by President Biden, it was by President Trump,” Romney told Chris Wallace on “Fox News Sunday.”

Within his party, Romney was in the minority Sunday. Later on the same show, Sen. Marco Rubio (R-Fla.) called a second impeachment trial of Trump “stupid” and “bad for America.” On ABC’s “This Week,” Sen. Rand Paul (R-Ky.) refused to say outright that the election was not stolen, echoing a number of other Republicans who have called for unity but refused to acknowledge that Biden won fairly, thereby perpetuating the falsehood that fueled the Capitol riots.

On “Meet the Press,” Sen. Mike Rounds (R-S.D.) said whether Trump had committed an impeachable offense was a “moot point” because he is no longer president. Sen. Tom Cotton (R-Ark.), who has argued that holding a trial after the president left office is beyond the Senate’s constitutional authority, said on Fox News that “the more I talk to other Republican senators, the more they’re beginning to line up behind the position I announced a couple weeks ago.” He did not specify which senators.

Meanwhile, RNC member ­Demetra DeMonte of Illinois sent a mass email to dozens of RNC members praising Trump and urging the RNC chairwoman and others to embrace a resolution she drafted opposing impeachment.

In a recent interview, RNC Chairwoman Ronna McDaniel told The Washington Post she opposed impeaching Trump. McDaniel declined to comment on the resolution.

But Bill Palatucci, a committee member from New Jersey and a close ally of former New Jersey governor Chris Christie, responded to the email, opposing the resolution. He said there was a constitutional argument that a trial could go forward.

“The RNC can best contribute to that healing process by acknowledging the role former president Trump played in the insurrection, condemn it and promise that we will do our best to make sure it never happens again,” Palatucci wrote.

A resolution, Palatucci said, could address whether a trial was in order, because there’s a constitutional argument for and against a trial.

Biden has largely refrained from weighing in on impeachment issues, though on Friday, he signaled an openness to delay the trial by two weeks so that the Senate could confirm more of his Cabinet nominees and take up his initial request of Congress: approval of a $1.9 trillion relief package to address the coronavirus pandemic and the economic fallout it has caused.

On ABC’s “This Week,” Sen. Amy Klobuchar (D-Minn.) said she believed the Senate could juggle all those tasks at once — perhaps confirming nominees in the mornings, running the impeachment trial in the afternoons and passing legislation at night.

Klobuchar also argued that not only is the trial constitutional, but there is a legal remedy beyond simply removing Trump from office — in this case, barring Trump from holding office again if he is convicted. She cited a report from the New York Times that revealed the former president had considered a plan to oust the acting attorney general to install at the top of the Justice Department an official more open to pursuing the baseless allegations that the election had been rigged for Biden.

“I think we’re going to get more and more evidence over the next few weeks, as if it’s not enough that he sent an angry mob down the Mall to invade the Capitol, didn’t try to stop it and a police officer was killed,” Klobuchar told ABC News journalist George Stephanopoulos. “I don’t really know what else you need to know. The facts were there.”

Rep. Madeleine Dean (D-Pa.), one of the House’s nine impeachment managers who essentially will serve as prosecutors during the Senate trial, said Sunday that the fact that 10 GOP House members voted for impeachment gave her hope that an increasing number of Republican senators will come to the same view.

“Ten was an historically high number,” Dean said on CNN’s “State of the Union.” “I find that to be heartening.”

Dean declined to say whether the allegations against Trump will be expanded to include recent revelations that he may have tried to do more to overturn the election results, including having considered ousting the acting attorney general to install a Justice Department official sympathetic to Trump’s unsubstantiated claims of election fraud.

“I think you will see that we will put together a case that is so compelling because the facts and the law reveal what this president did,” Dean said. “I will not be previewing our strategy and our case. . . . We will put forward a very strong case for impeachment, for disqualification, for conviction.”

Asked how long she anticipated the Senate trial to last, Dean said she “would expect that it would go faster” than the Senate’s first impeachment trial of Trump last January, which ended in an acquittal after three weeks.

“Some people would like us to turn the page,” Dean said.

She then invoked Biden’s words on the eve of his inauguration in which he said that healing from the losses brought by the coronavirus requires people to remember.

“We must remember,” Dean said Sunday, “that this impeachment trial . . . [is] those first very powerful steps toward unity in our country moving forward.”

Cat Zakrzewski contributed to this report.