“I think that we have pulled back a veil of behavior totally unacceptable to our founders, and that the public will see this with a clearer eye, an unblurred eye,” she said, adding: “Whatever happens, he has been impeached forever. And now these senators, though they don’t have the courage to assign the appropriate penalty, at least are recognizing that he did something wrong.”

Impeachment has been a tricky enterprise for both parties on both sides of the Capitol. In the Senate, where Democrats are in the minority, Mr. Trump’s impeachment trial — which is expected to conclude with his acquittal on Wednesday — forced vulnerable Republicans in swing states to align themselves with a president who brooks no dissent. They bristled at being painted as beholden to Mr. Trump, reacting angrily when the lead House impeachment manager referred to a news report that said Republican senators had been told their heads would be “on a pike” if they voted against him.

But in the House, impeachment was widely viewed as a gamble for moderates who represent districts where Mr. Trump is popular. While Ms. Pelosi gets generally good marks from her rank and file, some centrist members now grumble privately that she made some tactical missteps.

Her refusal to send the articles of impeachment to the Senate for several weeks after the House adopted them, which forced a delay in the Senate trial, generated blowback in swing districts, said Democratic lawmakers who insisted on anonymity to speak candidly. They cringed when Ms. Pelosi made a spectacle out of the eventual signing of the articles in January, when she distributed commemorative pens to colleagues. Critics said it undermined her own oft-stated message that this was a “somber” and “prayerful moment” for the country.

“Her whole thing was this was a solemn moment, and that was undignified to do a pen ceremony,” said one moderate Democrat in Congress, who insisted on anonymity for fear of retribution from the speaker. “A lot of us in the front line felt that wasn’t helpful.”