As the summer and the House Jan. 6 committee’s hearings began, former President Donald J. Trump was still a towering figure in Republican politics, able to pick winners in primary contests and force candidates to submit to a litmus test of denialism about his loss in the 2020 election.
Six months later, Mr. Trump is significantly diminished, a shrunken presence on the political landscape. His fade is partly a function of his own missteps and miscalculations in recent months. But it is also a product of the voluminous evidence assembled by the House committee and its ability to tell the story of his efforts to overturn the election in a compelling and accessible way.
In ways both raw and easily digested, and with an eye for vivid detail, the committee spooled out the episodic narrative of a president who was told repeatedly he had lost and that his claims of fraud were fanciful. But Mr. Trump continued pushing them anyway, plotted to reverse the outcome, stoked the fury of his supporters, summoned them to Washington and then stood by as the violence played out.
It was a turnabout in roles for a president who rose first to prominence and then to the White House on the basis of his feel for how to project himself on television.
Guided by a veteran television executive, the committee sprinkled the story with moments that stayed in the public consciousness, from Mr. Trump throwing his lunch in anger against the wall of the dining room just off the Oval Office to a claim that he lunged at a Secret Service agent driving his car when he was denied his desire to join his supporters at the Capitol.
On Monday — the second anniversary of Mr. Trump’s Twitter post urging his followers to come to Washington to protest his loss, promising it “will be wild!” — the committee wrapped up its case by lending the weight of the House to calls for Mr. Trump to be held criminally liable for his actions and making the case that he should never again be allowed to hold power.
“No man who would behave that way at that moment can ever serve in any position of authority in our nation again,” said Representative Liz Cheney, the Wyoming Republican who served as the committee’s vice chairwoman, referring to Mr. Trump’s unwillingness to intervene to stop the violence on Jan. 6, 2021. “He’s unfit for office.”
Understand the Events on Jan. 6
To emphasize that point, the committee did something Congress had never done before: It referred a former president to the Justice Department for criminal prosecution, a largely symbolic step but one that only added to the sense that Mr. Trump is starting his 2024 presidential campaign under a number of very dark legal clouds.
Federal prosecutors are investigating not only Mr. Trump’s efforts to thwart the results of the election, but also his mishandling of presidential records and classified material that he took with him when he left the White House. A prosecutor in Georgia is barreling ahead with an investigation of his efforts to reverse his election loss in that state, and his company, the Trump Organization, was convicted in New York this month of tax fraud.
Whether Mr. Trump’s legal woes and political missteps will keep him from winning his party’s nomination again is another matter.
Mr. Trump still has a durable base of support within the party, though just how large it is at this point is up for debate after a handful of public polls have shown more Republican voters backing Gov. Ron DeSantis of Florida as an alternative. Other potential candidates are also watching carefully, weighing their chances if they get into a race with a weakened Mr. Trump.
To some, the talk of Mr. Trump’s current fortunes is like a movie they have seen before, one in which the lead figure is left for dead only to rise again.
“There’s still a lot of people that support Donald Trump; there’s just no question about that,” said Rob Gleason, the former chairman of the Pennsylvania Republican Party. He pointed to stories that have dominated headlines, such as the number of Republicans whom Mr. Trump backed who lost their races, that he said simply have not seeped into the consciousness of his supporters.
“We assume people know too much,” he said. “They’re not following a lot of this stuff.”
Indeed, some Republicans said privately that the House select committee’s criminal referrals could serve to galvanize Mr. Trump’s supporters behind him, as was the case for a short time after the F.B.I. searched his club, Mar-a-Lago, in August, looking for additional classified documents.
Some other Republicans are more skeptical.
“I don’t think that anything can save Donald Trump,” said former Representative Carlos Curbelo, Republican of Florida. “He’s decidedly on the path to irrelevance. He reduces himself by the day.”
The rally speeches Mr. Trump gave at events during the midterm elections and his 2024 campaign announcement were largely centered on his grievances about 2020 or the investigations into his conduct — a formulation that some Republicans say is increasingly out of step with voters.
“This time is different,” Mr. Curbelo said, adding that six years ago, Mr. Trump was “new and interesting” and that people were curious what kind of leader he would be. “Now Donald Trump is old, predictable, obviously petty.”
Some of the candidates who most closely identified with Mr. Trump’s false claims about the 2020 election performed poorly in the midterm elections, and Republicans barely captured a House majority, despite a sitting Democratic president whose approval rating has been depressed.
“I think he’s been a diminishing figure for some time,” said former Representative Charlie Dent, Republican of Pennsylvania and a longtime critic of Mr. Trump.
Mr. Trump insisted on declaring a 2024 presidential campaign a week after the midterms, against the advice of nearly all his aides and allies, delivering a lackluster speech he read with minimal emotion from a teleprompter. He has held no public political events in the nearly five weeks since.
Instead, he has gotten attention for hosting a dinner at his members-only club and home in Florida with a Holocaust denier and Kanye West, the rap artist who has made a rapid descent into peddling antisemitism.
For many members of a party that would like to recover from three bruising election cycles, Mr. Trump has never felt more like a product of the past.
“Ironically, this is not too different from a reality TV series that’s run its course,” Mr. Curbelo said. “And people are just kind of over it, even his supporters.”