The Democratic presidential candidate Robert F. Kennedy Jr. got here to Capitol Hill on Thursday and pointedly declared that he’s neither an antisemite nor a racist, whereas giving a fiery protection of free speech and accusing the Biden administration and his political opponents of attempting to silence him.

Mr. Kennedy, an environmental lawyer who turned to anti-vaccine activism and has trafficked in conspiracy theories, was referring to the storm that erupted after The New York Post printed a video by which he told a private audience that Covid-19 “attacks certain races disproportionately” and should have been “ethnically targeted” to do extra hurt to white and Black folks than to Ashkenazi Jews and Chinese folks.

Mr. Kennedy appeared earlier than the House Select Subcommittee on the Weaponization of the Federal Government — a panel created by Republicans to conduct a wide-ranging investigation of federal legislation enforcement and nationwide safety companies. He stated he had “never been anti-vax” and had taken all advisable vaccines besides the coronavirus vaccine.

Thursday’s listening to was dedicated to allegations by Mr. Kennedy and Republicans that the Biden administration is attempting to censor folks with differing views. It was rooted in a lawsuit, filed final yr by the attorneys common of Missouri and Louisiana and often called Missouri v. Biden, that accused the administration of colluding with social media companies to suppress free speech on Covid-19, elections and different issues.

The subcommittee’s chairman, Representative Jim Jordan, Republican of Ohio and an acolyte of former President Donald J. Trump, opened the listening to by citing an email that emerged in that case, by which a White House official requested Twitter to take down a tweet by which Mr. Kennedy instructed — with out proof — that the baseball legend Hank Aaron might have died from the coronavirus vaccine.

The tweet, which was not taken down, stated Mr. Aaron’s dying was “part of a wave of suspicious deaths among elderly” following vaccination. There was no such wave of suspicious deaths. As Mr. Kennedy typically does, he phrased his language fastidiously; he didn’t explicitly hyperlink the vaccine to the deaths, however quite stated the deaths occurred “closely following administration of #COVID #vaccines.”

Thursday’s session had all of the makings of a Washington spectacle. A protracted line had shaped exterior the listening to room within the Rayburn House Office Building by the point Mr. Kennedy arrived. Kennedy supporters stood exterior the constructing holding a Kennedy 2024 banner.

Despite the theater, the listening to raised thorny questions on free speech in a democratic society: Is misinformation protected by the First Amendment? When is it acceptable for the federal authorities to hunt to tamp down the unfold of falsehoods?

Democrats accused Republicans of giving Mr. Kennedy a discussion board for bigotry and pseudoscience. “Free speech is not an absolute,” stated Delegate Stacey Plaskett of the Virgin Islands, the highest Democrat on the subcommittee. “The Supreme Court has stated that. And others’ free speech that is allowed — hateful, abusive rhetoric — does not need to be promoted in the halls of the People’s House.”

Even by Mr. Kennedy’s requirements for stoking controversy, his current feedback about Covid-19 had been surprising. Representative Debbie Wasserman Schultz, Democrat of Florida, who’s Jewish, tried unsuccessfully on Thursday to drive the panel into govt session; she insisted that Mr. Kennedy had violated House guidelines by making “despicable antisemitic and anti-Asian comments.” She additionally helped set up Democrats to signal a letter calling on Republican leaders to disinvite him from the listening to.

Mr. Kennedy waved the letter about throughout his opening remarks. “I know many of the people who wrote this letter,” he stated. “I don’t believe there’s a single person who signed this letter who believes I’m antisemitic.”

Mr. Kennedy has been steeped in Democratic politics for his whole life, however his marketing campaign has drawn supporters from the fringes of each political events. He has made frequent trigger with Republicans and Trump supporters who accuse the federal authorities of conspiring with social media firms to suppress conservative content material.

Thursday’s listening to was billed as a session to “examine the federal government’s role in censoring Americans, the Missouri v. Biden case and Big Tech’s collusion with out-of-control government agencies to silence speech.” One of the legal professionals concerned in that case, D. John Sauer, additionally testified, as did Emma-Jo Morris, a journalist at Breitbart News, and Maya Wiley, the president and chief govt of the Leadership Conference on Civil and Human Rights.

Mr. Kennedy confirmed a flash of the outdated Kennedy type, invoking his uncle, Senator Edward M. Kennedy of Massachusetts, a Democrat and legislative large who incessantly labored throughout the aisle. He known as for kindness and respect, recalling how his uncle introduced Senator Orrin G. Hatch, the Utah Republican with whom he partnered on main laws, to the Kennedy compound in Hyannis Port, Mass.

And Mr. Kennedy was joined by a former member of Congress: Dennis J. Kucinich, who served within the House as a Democrat from Ohio and is Mr. Kennedy’s marketing campaign supervisor.

“We need to elevate the Constitution of the United States, which was written for hard times,” Mr. Kennedy declared at one level, “and that has to be the premier compass for all of our activities.”

Amid the vitriol, members of each events did come collectively round a lament from Representative Gerald E. Connolly, Democrat of Virginia.

“I’ve been in this Congress 15 years, and I never thought we’d descend to this level of Orwellian dystopia,” Mr. Connolly stated.

Representatives Chip Roy, Republican of Texas, and Harriet M. Hageman, Republican of Wyoming, nodded their heads and smiled. “I agree with that,” they stated in unison.