False G.O.P. Ad Prompts QAnon Death Threats Against a Democratic Congressman

Representative Tom Malinowski, Democrat of New Jersey, is facing down death threats from QAnon supporters after the House Republicans’ campaign arm falsely accused him of lobbying to protect sexual predators.

QAnon supporters began targeting Mr. Malinowski, a first-term congressman, on Tuesday, after he led a bipartisan resolution condemning the movement, which spreads a baseless conspiracy theory that President Trump is battling a cabal of Democratic pedophiles.

QAnon believers seized on an advertisement released last month by the campaign arm, the National Republican Congressional Committee, that falsely claimed that Mr. Malinowski, then a lobbyist for Human Rights Watch, worked to block a provision in a 2006 crime bill that would have expanded registration requirements for sex offenders.

Death threats and other harassing messages have since poured into Mr. Malinowski’s office in Washington. In an interview on Wednesday, he called the threats “a direct result” of the advertisement, noting that the calls his office had received cited its central accusation.

“We’ve been warning the Republicans running this play for at least the last two or three weeks that they were playing with fire,” he said. “Now the match has been lit.”

The threats against Mr. Malinowski were earlier reported by BuzzFeed News.

QAnon, the New York Times columnist Kevin Roose has explained, is the umbrella term for a sprawling set of internet conspiracy theories that claim, falsely, that the world is run by a group of Satan-worshiping pedophiles who are plotting against Mr. Trump while operating a global child sex-trafficking ring. The F.B.I. has warned that QAnon poses a potential domestic terrorism threat.

The attack ad against Mr. Malinowski played directly to the group’s chief charge.

“In every city, in every neighborhood, around every corner, sex offenders are living among us,” the narrator of the ad intoned.

“Tom Malinowski chose sex offenders over your family,” the ad said.

A separate document circulated by Republican officials repeated the claim, specifically stating that Mr. Malinowski “worked to ensure sex offenders who violated children” would not have to join the registry.

Mr. Malinowski, a former State Department official in the Obama administration, has said he did not work on that bill — a statement corroborated by Human Rights Watch — and that his portfolio at the organization was focused on foreign policy matters.

But the campaign arm doubled down on its claim on Wednesday in response to the BuzzFeed News report.

“The only person who bears responsibility here is Tom Malinowski for his decision to lobby against the creation of a national sex offender registry,” Maggie Abboud, a spokeswoman for the committee, said in a statement, calling the congressman’s actions “disgusting.” “Congressman Malinowski must live with the consequences of his actions.”

Mr. Malinowski said he had confronted Representative Tom Emmer of Minnesota, the National Republican Congressional Committee’s chairman, on Tuesday evening on the House floor about the QAnon death threats inspired by his committee’s ads. Mr. Emmer, he said, denied knowing what QAnon was and said that he was not responsible for what others did with the committee’s campaign material.