WASHINGTON — Within hours of the brutal attack last month on Paul Pelosi, the husband of the speaker of the House, activists and media outlets on the right began circulating groundless claims — nearly all of them sinister, and many homophobic — casting doubt on what had happened.

Some Republican officials quickly joined in, rushing to suggest that the bludgeoning of an octogenarian by a suspect obsessed with right-wing conspiracy theories was something else altogether, dismissing it as an inside job, a lover’s quarrel or worse.

The misinformation came from all levels of Republican politics. A U.S. senator circulated the view that “none of us will ever know” what really happened at the Pelosis’ San Francisco home. A senior Republican congressman referred to the attacker as a “nudist hippie male prostitute,” baselessly asserting that the suspect had a personal relationship with Mr. Pelosi. Former President Donald J. Trump questioned whether the attack might have been staged.

The world’s richest man helped amplify the stories. But none of it was true.

Here are 21 of the elected officials, candidates and other prominent figures who spread misinformation or cast doubt on the attack.

In tweets, podcasts and TV appearances, these figures questioned whether the public was being told the full story of what happened and in some cases spread theories that were unfounded.

Elected officials and candidates

Senator Ted Cruz

Republican of Texas

Amplified doubts that all facts were being disclosed.

Representative Marjorie Taylor Greene

Republican of Georgia

Suggested Mr. Pelosi knew his attacker.

Representative Clay Higgins

Republican of Louisiana

Suggested the attack involved male prostitution.

Lt. Gov. Mark Robinson

Republican of North Carolina

Raised doubts about the details of the attack.

Mary Williams Benefield

Republican statehouse candidate, Georgia

Suggested the attack might have been staged.

Royce White

Republican statehouse candidate, Minnesota

Claimed the attack involved an extramarital gay affair.

State Senator Wendy Rogers

Republican of Arizona

Suggested the attack might have been staged.

State Representative Anthony Sabatini

Republican of Florida

Suggested that the Pelosis are hiding vital information.

Representative Claudia Tenney

Republican of New York

Amplified a conspiracy theory about an extramarital gay affair.

Prominent figures

Glenn Beck

Conservative commentator

Raised doubts about the details of the attack.

Tucker Carlson

Fox News host

Raised doubts about the details of the attack.

Dinesh D’Souza

Conservative commentator

Claimed the attack involved an extramarital gay affair.

Ryan Fournier

Founder, Students for Trump

Claimed details about the attacker were fabricated.

Sebastian Gorka

Former Trump adviser and podcast host

Raised doubts about the details of the attack.

Pete Hegseth

Fox News host

Raised doubts that all facts were being disclosed.

Megyn Kelly

Talk show host

Raised doubts that all facts were being disclosed.

Elon Musk

Chief executive of Twitter and Tesla

Amplified a conspiracy theory about male prostitution.

Devin Nunes

Former representative of California

Repeated a false report that the attacker was in his underwear.

Michael Savage

Talk show host

Raised doubts that all facts were being disclosed.

Roger Stone

Trump associate

Suggested the attack was staged.

Donald J. Trump

Former president

Suggested the attack was staged.

The flood of falsehoods showed how ingrained misinformation has become inside the G.O.P., where the reflexive response of the rank and file — and even a few prominent figures — to anything that might cast a negative light on the right is to deflect with more fictional claims, creating a vicious cycle that muddies facts, shifts blame and minimizes violence.

It happened after the Jan. 6, 2021, attack on the Capitol, which was inspired by Mr. Trump’s lie of a stolen election, and in turn gave rise to more falsehoods, as Republicans and their right-wing allies tried to play down, deny or invent a different story for what happened, including groundlessly blaming the F.B.I. and antifa. Mr. Pelosi’s attacker is said to have believed some of those tales.

“This is the dynamic as it plays out,” said Brian Hughes, a professor at American University who studies radicalism and extremism. “The conspiracy theory prompts an act of violence; that act of violence needs to be disavowed, and it can only be disavowed by more conspiracy theories, which prompts more violence.”

The Justice Department moved swiftly to bring criminal charges against the suspect in the attack, David DePape, 42, who prosecutors said broke into the Pelosi home intending to kidnap Ms. Pelosi and shatter her kneecaps, and assaulted her husband with a hammer, leaving him with a cracked skull. The San Francisco district attorney said it was imperative for prosecutors to present the facts to the public, given the misinformation circulating widely about the case.

But by then, it was far too late. In a pattern that has become commonplace, a parade of Republicans — helped along by right-wing media personalities including the Fox New host Tucker Carlson, and prominent people including the newly installed Twitter owner Elon Musk, the world’s wealthiest man — had already abetted the viral spread of lies about the attack, distorting the account of what happened before facts could get in the way. Finding life on far-right websites and the so-called dark web, conspiracy theories and falsehoods leaped from the fringes to the mainstream.

While many Republican leaders denounced the violence and some, including former Vice President Mike Pence, expressed sympathy for the Pelosis, none of them publicly condemned the falsehoods their colleagues were elevating or did anything to push back on the false narrative. That left others to fill the void.

“Just produce the police body cam, — why is that so hard?” Mr. Carlson demanded on his show on Wednesday night. Addressing those criticizing the conspiracy theorizing, he added: “We’re not the crazy people; you’re the liars. There’s nothing wrong with asking questions, period.”

The disinformation surrounding the attack on Mr. Pelosi presented many of the standard elements of alt-right conspiracy theories, which relish a culture of “do your own research,” casting skepticism on official accounts, and tend to focus on lurid sexual activities or issues related to children, often driven by a fear of society becoming immoral.

Nina Jankowicz, a disinformation expert, said no amount of evidence — be it police body camera footage or anything else — could get in the way of such falsehoods in the eyes of those who do not want to believe facts.

“It doesn’t matter when there are documents or sworn testimony claiming something is, in fact, not the case,” Ms. Jankowicz said. “There will be an elaborate reframing effort. If the footage was released, people would claim it was fabricated. There’s no bottom.”

Many of the Republicans who amplified the fiction couched their comments as jokes, effectively pre-empting any criticism by suggesting they might not be serious. Hours after the attack, Donald Trump Jr., the former president’s son, shared online a viral image of a costume that included an oversized pair of men’s briefs and a hammer, remarking “the internet remains undefeated.”

A spokesman for Mr. Trump said he “simply posted a joke meme and has always rejected political violence in all forms.”

Representative Claudia Tenney, Republican of New York, circulated a photograph on Twitter that showed a group of young, white men holding oversized hammers beside a gay Pride flag, commenting simply: “LOL.”

Ms. Tenney did not respond to a request for comment.

It is not clear whether the elected officials and media personalities who have trafficked in falsehoods believe the conspiracy theories they are elevating, or simply want to be rewarded by their right-wing base. According to public polling, as many as 70 percent of Republicans still believe that Mr. Trump was the true winner of the 2020 election.

Mary Williams Benefield, a Republican running for a seat in Georgia’s statehouse, said she had responded online to a tweet suggesting the attack was staged because “the official narrative is unwilling to present all the facts.”

“Maybe their daughter has a film crew shooting a documentary on this too,” wrote the mother of three and former music teacher at a church school, making a reference to newly surfaced footage from a documentary Ms. Pelosi’s daughter Alexandra was filming that showed the speaker in a secure location during the Jan. 6 riot.

In an interview, Ms. Benefield brought up a report that the police have debunked, which wrongly asserted that the intruder was dressed only in his underwear. The Fox News affiliate that originally reported the detail issued a correction saying the article had previously “misstated what clothing the suspect was wearing.”

That did nothing to change Ms. Benefield’s mind.

“There’s a lot of questions that need to be asked before there’s any legitimacy,” she said.

According to federal charging documents, Mr. DePape was enthralled by the conspiracy theories that have portrayed Ms. Pelosi as an enemy of the country. His online activities show him ranting about the 2020 election being stolen, seeming to deny the gassing of Jews at Auschwitz and claiming that schoolteachers were grooming children to be transgender.

His attorney has said he planned to argue that Mr. DePape was so influenced by disinformation that it should be considered a mitigating circumstance.