WASHINGTON — The day after Josh Hawley became the first Republican senator to say he would indulge President Trump’s demand that lawmakers try to overturn the election, a reporter asked if he thought the gambit would make him unpopular with his colleagues.

“More than I already am?” he retorted.

Even before Mr. Hawley lodged what was certain to be a futile objection to Congress’s certification of the results, the 41-year-old senator — regarded as a rising Republican star who could one day run for president — was far from the chamber’s most popular lawmaker.

His insistence on pressing the challenge after a violent mob egged on by Mr. Trump stormed the Capitol to protest President-elect Joseph R. Biden Jr.’s victory, endangering the entire Congress and the vice president in a day of terror that left at least five people dead, has earned him pariah status in Washington.

But while Mr. Hawley’s role in the riot may have left him shunned — at least for now — in official circles, it may only have improved his stock with his party’s base in his home state, which remains deeply loyal to Mr. Trump.

His fellow Republicans in the Senate lined up to blame Mr. Hawley for the riot. The editorial boards of major newspapers in Missouri accused him of having “blood on his hands” and called on him to resign. His publisher canceled his book deal and his erstwhile mentor called his efforts to get Mr. Hawley elected to the Senate “the biggest mistake I’ve ever made.”

“But for him, it wouldn’t have happened,” former Senator John C. Danforth of Missouri, the Republican elder statesman, told The Kansas City Star of his former protégé’s role in the riot.

Mr. Hawley has remained defiant, arguing Wednesday evening that the electoral count in Congress was the proper venue to debate his concerns about fraud in the balloting, though he never made a specific charge of wrongdoing.

“I will never apologize for giving voice to the millions of Missourians and Americans who have concerns about the integrity of our elections,” Mr. Hawley said in a statement. “That’s my job, and I will keep doing it.”

But many Republicans dismissed his effort as grandstanding intended to further his own political ambitions. Some Democratic senators demanded his resignation. And on Friday, Mr. Biden said that Mr. Hawley and Senator Ted Cruz, Republican of Texas, were part of “the big lie” that had animated Mr. Trump’s refusal to concede, invoking Joseph Goebbels, Nazi Germany’s minister of propaganda.

Mr. Hawley lashed out at Mr. Biden, accusing him of “undignified, immature, and intemperate behavior” and calling on him to “retract these sick comments.”

Hours after the mob was cleared from the Capitol on Wednesday, Mr. Hawley refused to drop his challenge to the election results, objecting to Pennsylvania’s slate of electors and forcing both chambers into a two-hour debate on his call to throw out millions of the state’s votes.

An image of Senator Mitt Romney, Republican of Utah, sitting behind Mr. Hawley and glaring as the Missourian gazed into television cameras and made his case from the Senate floor became an instant meme. Mr. Hawley’s challenge was rejected by broad bipartisan margins, with only six Republican senators joining him in supporting it.

By Thursday, the fallout reached beyond the scorn of his colleagues. The publisher Simon & Schuster said it was canceling publication of his book “The Tyranny of Big Tech,” citing “his role in what became a dangerous threat.” Mr. Hawley responded with an angry statement that called his former publisher a “woke mob” and described their decision as “a direct assault on the First Amendment.”

“This could not be more Orwellian,” Mr. Hawley said. “This is the left trying to cancel everyone they don’t approve of.”

Yet some of the harshest criticism came from his own party. His bid was in direct defiance of Senator Mitch McConnell of Kentucky, the Republican leader, who had implored his members not to challenge the election results and force a divisive vote when there was no chance of changing the outcome. Searing blowback came from other Republicans who are also considered 2024 presidential contenders and could find themselves running against Mr. Hawley in a crowded primary.

“Senator Hawley was doing something that was really dumbass,” Senator Ben Sasse, Republican of Nebraska, told NPR. “This was a stunt. It was a terrible, terrible idea. And you don’t lie to the American people. And that’s what’s been going on.”

Senator Tom Cotton, Republican of Arkansas, also lashed out at Mr. Hawley in a Fox News interview on Thursday — though he did not call him out by name — for indulging the effort to overturn the election.

“You have some senators who, for political advantage, were giving false hope to their supporters, misleading them into thinking that somehow yesterday’s actions in Congress could reverse the results of the election,” Mr. Cotton said in a clip circulated by his office. “That was never going to happen, yet these senators, as insurrectionists literally stormed the Capitol, were sending out fund-raising emails. That shouldn’t have happened, and it’s got to stop now.”

Scott Jennings, a Republican strategist and former aide to Mr. McConnell, said in an interview that he believed Mr. Hawley’s decision to raise his objection to Pennsylvania’s electors hours after the mob stormed the Capitol was a “disqualifying” display of judgment.

“Once the Capitol had been literally occupied, how can you give quarter to the viewpoint that caused the occupation?” Mr. Jennings said. “What would it have taken for Josh Hawley to withdraw his objection? How do you come back from that?”

Some Democrats said Mr. Hawley never could. Senators Patty Murray of Washington, the No. 3 Democrat, and Chris Coons of Delaware, one of Mr. Biden’s closest allies in the chamber, demanded that Mr. Hawley resign. Senator Tim Kaine, Democrat of Virginia, argued that the Senate should censure him.

“Any senator who stands up and supports the power of force over the power of democracy has broken their oath of office,” Ms. Murray said in a statement.

Still, as Republicans struggled to recover from an episode that has exposed deep rifts in their ranks, there was evidence that Mr. Hawley’s actions on Wednesday had boosted his standing with influential elements of his party.

The Senate Conservatives Fund, a political action committee founded by former Senator Jim DeMint of South Carolina, defended Mr. Hawley and urged its members to donate to his campaign.

“The junior senator from Missouri’s decision to object to the election results showed tremendous courage,” the fund-raising pitch, signed by Mary Vought, the fund’s executive director, said. “Conservatives should stand shoulder to shoulder with him in defending our cherished values.”

Christian Morgan, a St. Louis-based strategist and former top aide to Representative Ann Wagner, Republican of Missouri, also defended Mr. Hawley.

“Bernie Sanders did not cause the attempted mass assassination of Republican Members of Congress, James Hodgkinson did,” Mr. Morgan wrote on Twitter, referring to a liberal activist who opened fire on Republican lawmakers during a softball practice in 2017. “Josh Hawley & Ted Cruz did not cause an angry mob to invade the Capitol and murder a Capitol Police.”

Leaders of the Missouri Republican Party did not respond to interview requests on Friday. But their most recent Facebook post — celebrating National Missouri Day and written before the chaos on Wednesday — started drawing comments suggesting that party leaders begin searching for a candidate to mount a primary challenge to Roy Blunt, Missouri’s senior Republican senator, who voted to certify the election results.

The former head of Missouri’s Republican Party, Jean Evans, said that she resigned from the position before the events on Wednesday in response to people demanding that the party bus people to protest in Washington and calling for violent behavior.

“I was concerned and alarmed by what I was hearing from certain elements within the party calling for a coup,” Ms. Evans told a local television station.