In the conspiracy-obsessed echo chambers of conservative talk radio and far-right websites, Sen. Mitt Romney has some explaining to do — answering for ties to the Ukrainian gas company that put Joe Biden’s son on its board, and accounting for conversations with House Speaker Nancy Pelosi about Republican support for impeaching President Trump.

In reality, neither claim is true. No meaningful ties exist between the Utah Republican and Burisma, and he had no such conversation with Pelosi.

The flood of baseless attacks and misleading innuendo buffeting Romney, which began after he became a rare Republican to express concern about Trump’s interactions with the Ukrainian president, serves as a preview of the viral attacks likely to be unleashed on GOP lawmakers if they buck their president during an impeachment showdown that Trump has denounced as a “coup.”

Holding the line on impeachment, particularly by pressuring Republicans to remain in lockstep behind Trump, has quickly become the core mission of a squadron of pro-Trump television personalities, talk radio hosts, conservative blogs, fringe Facebook groups and Twitter accounts. Together, these voices form an alternative worldview, built on hostility to mainstream news media and capable of shaping the information consumed by core Republican voters.

“It’s tribal, and there are Trump cultists in the Republican Party who are constantly going to try to manufacture anything against the president’s critics,” said Mike Murphy, a Republican strategist and Trump critic whose clients have included Romney as well as the late senator John McCain of Arizona. “The easiest place to manufacture and disseminate that stuff is online.”

Romney is not the only Republican to feel the heat in recent days. Sen. Charles E. Grassley (R-Iowa), after defending the whistleblower who raised alarm about Trump and Ukraine, faced withering criticism from the Gateway Pundit, a far-right blog that gained White House press credentials in 2017. “So much for the Republican leaders in the Senate defending President Trump against the continuation of the attempted coup,” the site warned.

Sen. Ben Sasse (R-Neb.), who said he was troubled by the whistleblower complaint, was accused by Big League Politics, a conservative website founded by former Breitbart employees, of “stabbing [Trump] in the back.” Rep. Adam Kinzinger (R-Ill.), who rebuked Trump for tweeting an ally’s prediction that removing him from office would spark “civil war,” was ridiculed as “garbage” and, in the telling of an Infowars editor, an example of “spineless sellouts.”

A Republican congressional aide who spoke on the condition of anonymity to describe dynamics within the party said: “These kinds of tactics are about one thing: scaring Republicans from getting out of line.”

The Romney episode offers a case study in how Trump’s allies respond when a Republican shows signs of breaking ranks.

Many Trump backers have long been suspicious of Romney, the 2012 Republican presidential nominee and former Massachusetts governor, who in the 2016 primary delivered a speech calling Trump a “phony” and a “fraud.” As a Senate candidate last year and since taking office, Romney has expressed openness to working with the president, and his criticism has been muted.

The day after details emerged about Trump’s phone call with the Ukrainian leader, Romney issued a brief statement on social media that signaled disapproval, though with a hedge.

“If the President asked or pressured Ukraine’s president to investigate his political rival, either directly or through his personal attorney, it would be troubling in the extreme,” he wrote on Sept. 22. “Critical for the facts to come out.”

The next day, Bill Kristol, the conservative columnist, speculated on MSNBC that Romney’s comments “helped reassure” Pelosi as House Democrats moved toward an impeachment inquiry.

The comment appeared to be the fodder for a fabricated notion by Rush Limbaugh, the pro-Trump radio host who claimed on Sept. 25 that Romney “had phone calls or meetings, whatever, with Pelosi and assured her that there was Republican support to remove Trump.” The baseless claim, denied by Romney’s office and debunked by a fact check, nevertheless drove conspiracy theories on conservative news sites, which also celebrated a video posted by Trump on Twitter mocking the senator for losing the 2012 presidential election.

Meanwhile, Romney reiterated to reporters on Capitol Hill that the Ukraine controversy “remains troubling in the extreme. It’s deeply troubling.”

The day after that, the attempt to discredit Romney intensified with a story in the American Thinker, a conservative news and opinion site founded by Thomas Lifson, whose writing also appears — without his permission, he says — on the conspiracy theory site the Liberty Beacon.

In an article on Sept. 26, Lifson declared that a Romney adviser was on Burisma’s board of directors, suggesting that the connection was embarrassing for the Republican senator.

The article referred to Joseph Cofer Black, an ex-CIA official who had been a special adviser for foreign policy and national security on Romney’s 2012 presidential campaign.

But there is no sign of any connection between Romney and Burisma. Black was one of at least two dozen advisers on the campaign with his title, and he has no current affiliation with Romney. Moreover, according to Burisma’s website, Black was added to the board in 2017, years after the Romney campaign ended.

Black did not respond to a request for comment placed through the Baltic International Bank, on whose supervisory board he also serves.

Burisma’s owner came under scrutiny by Ukrainian prosecutors for possible abuse of power and unlawful enrichment, but the investigation was dormant when Biden pressured Ukraine to fire the top prosecutor, and none of the references to Black in conservative media carry any evidence that he was a target of the probe.

Without evidence or explanation, Lifson suggested it was an “odd coincidence” that Romney’s former adviser was associated with Burisma. Lifson described Black as a “CIA spook,” language also employed in the far-right fringes of the Internet to attack the whistleblower who brought forth concerns about Trump’s conversation with Ukraine’s president, Volodymyr Zelensky.

Lifson remained adamant in an email to The Washington Post, saying, “As I wrote in the blog piece, there are a lot of coincidences.”

To Romney allies, the framing was clear. “It’s simple guilt by association,” said Murphy, the GOP strategist.

Lifson’s article spread quickly in the right-wing information ecosystem, shared more than 18,000 times on Facebook, according to the social monitoring platform CrowdTangle. It appeared on a page promoting “LEXIT,” or a “Latino awakening” and exit from the Democratic Party, and in a group boasting nearly 50,000 members that goes by the name “Donald Trump — God’s choice for America!!!” The article drove commentary on Reddit, the popular online messaging forum, and it gained traction among Twitter accounts that mobilize around the “Make America Great Again” mantra for the pro-Trump movement.

The claims found their way to the most prominent parts of social media, where queries about Romney on Facebook at one point returned three articles by far-right outlets. Among them was Breitbart, which had picked up the story from the American Thinker.

“It’s scary how quickly false information can spread,” said Liz Johnson, a spokeswoman for Romney.

The onslaught was especially revealing because it showed how threads of factual information can be spun into a false narrative seemingly resistant to simple denial.

Information does not have to be fake or stolen to succeed in manipulating online discourse, experts warn. In fact, the underlying truth of misleading narratives can make them more insidious, and more effective in manipulating public perception as the 2020 election looms.

“The best disinformation is built around a kernel of truth,” said Jakub Kalensky, a senior fellow at the Atlantic Council focusing on Russian information operations. “It’s the framing that makes it dangerous.”

Clarification: This article has been revised to include Thomas Lifson’s statement that he does not write for the Liberty Beacon, as the story originally said, and that his writing appears there without his knowledge or permission. The Liberty Beacon didn’t respond to a request for comment.