The F.B.I. director, Kash Patel, suggested on Tuesday that he was open to sending federal agents to polling places, raising alarms from Democrats that the Trump administration would act aggressively to assert greater control over the coming elections.
The remarks, made during testimony before the Senate Judiciary Committee, stood at odds with earlier comments indicating that he did not intend to send federal agents to polling places around the country. However, when Senator Peter Welch, Democrat of Vermont, pressed the issue, Mr. Patel seemed to reverse course.
“I thought you weren’t going to be sending people to the polls,” Mr. Welch said.
“When did you hear that? Just another lie,” Mr. Patel declared, raising his voice.
Mr. Welch revisited the issue. “So you are sending F.B.I. agents to the polls?”
“We have election crisis coordinators manned at all 56 field offices,” Mr. Patel replied, appearing to refer to what are known as election crime coordinators. “Election integrity is of paramount importance. This F.B.I. will not shy away from that effort.”
Under the law, armed federal officers or military personnel are barred from being deployed “at any place where a general or special election is held.” The chairman of the Joint Chiefs of Staff said in a letter to a Democratic senator last month that there were “no plans” for the armed forces to deploy troops to polling stations for the midterm elections.
As President Trump has ramped up his efforts to cast doubt on the integrity of the vote in an election his party might lose, Democrats have sought assurances from Trump administration officials that they will follow the law, which carries a potential five-year prison sentence for any violations.
The president regularly declares the 2020 election he lost was “rigged,” and has said the only way Democrats can win control of Congress this year is by cheating. The claims have only fueled broader concerns that loyalists within the administration may wage a pressure campaign against state officials to produce election results favorable to Mr. Trump’s party.
When he was first asked about the issue at the hearing, Mr. Patel vowed to “follow the law.”
“If there’s a reason to go there because there’s been a violation, we will, otherwise we won’t,” he added, noting that “we’re going to house our agents and intel analysts in our field offices.”
Historically, the Justice Department used workers at its public integrity unit to consult with prosecutors and agents around the country on sensitive investigative issues around elections. But the Trump administration dismantled that unit last year, leaving it unclear who in the department and the F.B.I. would handle such critical decisions in the final days of the election cycle.
Mr. Welch expressed alarm at Mr. Patel’s responses, saying they suggested he could harness the power of the federal government to try to affect election outcomes.
“This is about whether the United States citizens — Republicans, Democrats, independents — are the deciders of this election or there is election interference led by the F.B.I. and the Trump administration,” Mr. Welch said.
The senator prodded further. “Do you pledge that you will not in any way interfere in the will of the American people when they go to the polls in November?”
Mr. Patel sidestepped the issue, saying instead: “I pledge unequivocally that I will not participate in your charade of lies.”
An angry argument ensued, with the pair exchanging attacks. The senator denounced the F.B.I. director as a “panderer” to Mr. Trump, and Mr. Patel suggested Mr. Welch’s personal finances were suspicious.
“Let’s knock it off,” said Senator John Cornyn, Republican of Texas, as he tried to lower the temperature in the hearing room.
It did not work.
“Everybody sees you for the complete and total fraud you are,” Mr. Patel said angrily to Mr. Welch.
The Vermont senator then challenged Mr. Patel over his travel, in which he often combines work with recreational activities. During a trip to Italy, Mr. Patel spent time at the Olympics in Milan, during which he was filmed chugging a beer with the men’s hockey team after they won gold.
“I go where I want to go, after delivering the most prolific crime reduction in U.S. history,” Mr. Patel said. “What you’ll never understand is the players who are my friends invited me to the locker room.”
Mr. Patel was also pressed on whether counterintelligence agents had opened an investigation into how a wealthy Russian oligarch paid for part of the wedding celebrations for President Trump’s son Donald Trump Jr.
“It may involve some intelligence degradation, and I would like to know what steps you are taking to investigate,” said Senator Richard Blumenthal, Democrat of Connecticut.
He added, “I think there’s a potential for compromise in intelligence and also the possibility of improper influence.”
Mr. Patel was noncommittal.
“We will look at whatever information comes our way,” he said.
In one of the stranger exchanges, Mr. Patel repeatedly fielded questions about bestiality, part of a recent change in F.B.I. policy that loosened hiring standards, including by no longer automatically disqualifying job candidates who have participated in sexual activity with animals. The change, he said, was made out of consideration for people who may have been forced, either as children or sex-trafficking victims, to participate in such conduct.
“We did not want to punish victims of bestiality, victims who were trafficked,” Mr. Patel said. While he did not elaborate, there have been cases in which children or others were forced to engage in sex with animals.
Previously, the director said, the F.B.I. had automatically disqualified anyone who had engaged in such conduct, no matter the circumstances. Lawmakers seemed flummoxed by the explanation.
“Either side of what, the bestiality?” Senator John Kennedy, Republican of Louisiana, asked. “So you disqualified the animal?”
Mr. Patel replied, laughing: “We have great canines, but we’re not going to disqualify them.”
At other points, the hearing veered into sniping.
Senator Cory Booker, Democrat of New Jersey, said Mr. Patel had acted “like a thug” in using law enforcement agents to subpoena reporters.
“We are not targeting reporters at any point in time,” Mr. Patel replied.
“We don’t have an F.B.I. director, we have a lackey here, and frankly not even a good lackey, he’s an incompetent lackey,” Mr. Booker said. “This is a mockery and a sham.”
As the two men argued, Senator Charles E. Grassley, Republican of Iowa, sought to end the exchange.
“Are you done now? Are you ready to shut up?” Mr. Grassley, the committee chairman, growled at Mr. Booker.
