Shalala, who served as Clinton’s Health and Human Services secretary, said she has told fellow freshmen that if the decision is based on politics “that we are just going to be wrong, and the American people are smart enough to figure that out.”

Dozens of Democrats said similarly they were trying to set aside political considerations. Still, those lawmakers have ended up on all sides of the debate. 

Rep. Peter Welch (D-Vt.), who has urged colleagues in private meetings to move with caution, said it has been difficult for Democrats to cast aside politics when a growing number of the party’s 20-odd presidential candidates have already come out in support of impeachment.  

That contest to win the hearts and minds of party regulars is playing out in a largely separate universe from House Democrats, 31 of whom represent districts that Trump won in 2016.

“This has got to be seen as on the level,” Welch said. “They want to get the nomination, so they’re appealing to the base. Whatever we do has to be credible beyond the Democratic base.”

To many lawmakers, no single person will have more bearing on how things proceed than Mueller, who is so far resisting Democrats’ wishes to make him the star witness of a must-see televised hearing.

Others are thinking about process, not personalities — a point of view that many in the party leadership are avidly promoting. Gather facts, subpoena documents, win in court, and the impeachment question will answer itself, many Democrats insist — particularly the corps of new lawmakers who ousted Republicans to hand their party their majority.

“I’m thinking about the next 50 years,” said Rep. Mikie Sherrill, a freshman representing the northern New Jersey suburbs. “As we look back on this process, are we doing the very best for the country? Are we making sure that the steps that we’re taking now are going to leave our democratic institutions in the best possible place?”

The most staunch anti-Trump Democrats are ready to charge into the impeachment battle, almost all fully cognizant that it might not make the most political sense and the odds are stacked heavily against their actually ousting the president. 

But they are facing history’s judgment. 

“It will probably fire up his base. And they’ll feel like he’s being victimized, especially if we cannot complete the whole process,” said Rep. William Lacy Clay (D-Mo.), an 18-year veteran from a district around St. Louis. He cannot sit by and watch Trump anymore. “It’s gotten to the point where we have to do something.”

On multiple occasions in 2017 and 2018, Trump threatened to interfere in the licensing deals for media companies he thought were not covering him fairly.

“The fact that he was willing to use an arm of the government to censor media to me was clearly an impeachable offense and an abuse of power,” said Rep. John Yarmuth (D-Ky.), a former newspaper publisher in Louisville. 

These members are part of a corps of Democratic early believers who say that Trump’s presidency poses an existential threat to the nation and that the party should look for ways to remove him from office at the earliest possible moment. They forced a vote in late 2017 on a resolution to impeach Trump over racially tinged remarks he made in the wake of the neo-Nazi riots in Charlottesville earlier that year, as well as several other actions, and 58 Democrats voted for the measure.

But several dozen of those Democrats were basically venting their anger, a free vote to protest Trump’s actions without actually beginning impeachment.

The issue took on real meaning with Democrats winning the House majority and the release of the Mueller report. The tide turned with the former special counsel’s 10-minute summation in late May.  

More than half a dozen Democrats broke against Pelosi’s position in the past few weeks, many usually loyal to the woman who has led their caucus for 16½ years — Democrats like Bennie Thompson (Miss.), chairman of the Homeland Security Committee and a senior member of the Congressional Black Caucus. 

Back home in Mississippi for the Memorial Day recess, Thompson found everyone asking about Mueller’s findings. 

“That’s all they were talking about in the barbershop,” he said, prompting him to publicly join the impeachment converts.

Rep. Cedric L. Richmond (D-La.), a former CBC chairman, reached the same conclusion. “History is going to ask, ‘What were we doing when all of these things were going on?’ And I don’t want to be judged in history asleep at the wheel,” Richmond said. 

In Philadelphia, Rep. Brendan Boyle, the son of an Irish immigrant father, said the “final straw” came watching Mueller on TV describing the report and, as Boyle saw it, making clear Trump would have been indicted if he were not the sitting president.

About 50 miles west of Boston, Rep. Jim McGovern’s mother spent two years badgering him with the same questions: “Have you gotten rid of him yet? Is he out of office yet?” 

As chairman of the Rules Committee, McGovern is Pelosi’s handpicked parliamentary expert, a loyal lieutenant who executes her game plan on every key piece of legislation that reaches the House floor. McGovern said it was the “culmination of things” that left him unable to hold back. He announced his support for impeachment a day after Mueller spoke at the Justice Department.  

“My mother is now happier with me than she’s been in the last two years,” he said. 

These Democrats are grappling over which precedent would be worse: Not launching impeachment might signal to future presidents that such behavior will not result in any investigation, while an impeachment that ends in a deadlocked Senate might set a precedent that Trump’s behavior should not be considered worthy of removal. 

“So I actually see risk either way you go,” Boyle said. 

Karoun Demirjian contributed to this report.