“At the time, I did my best to communicate, and clearly I fell short,” David Chipman said as part of multiple attempts to walk back controversial statements during a Senate hearing. “I will try to do better.”

Chipman, the former ATF agent whom President Joe Biden nominated to head the agency, had several heated exchanges with Republican Senators on the Judiciary Committee Wednesday. He faced repeated questions about his past comments advocating expansive new gun bans, belittling first-time gun owners, and falsely claiming helicopters were shot down during the disastrous 1993 siege of a cult compound in Waco, Texas. Chipman apologized for several of his previous comments while standing behind policy positions he took while working for multiple gun-control organizations.

ATF directors have been difficult to confirm in recent years with the last confirmation coming in 2011. Chipman’s time working for gun-control groups already made his confirmation a difficult task in a divided Senate where moderate Democrats have significant say over the confirmation. His record of controversial statements and continued support for gun-control policies well beyond what many Democrats in the Senate support could hurt Chipman’s chances of getting confirmed to the role.

Chipman stood by his call to ban popular rifles including the AR-15, which he described as “particularly lethal,” during his testimony. He said he not only supports a ban on the sale of guns but also a requirement to register currently-owned ones with the ATF. He said AR-15s and other guns should be regulated under the National Firearms Act (NFA), which would subject them to a $200 tax stamp and put the same restriction on them as is currently applied to machine guns.

“With respect to the AR-15, I support a ban,” Chipman said before saying he believes the “assault weapons” ban proposed by Democratic Senator Dianne Feinstein does not go far enough. “Senator Feinstein’s bill did not address those firearms that are currently in the possession of Americans. My view as an advocate, which would be quite different than someone actually enforcing the law on the books, was that those firearms could be treated under the NFA and regulated that way, which would deal with those currently in the possession of Americans.”

However, he refused to give a definition despite repeated direct questions about how he would define the class of guns he supports banning.

“Assault weapons would be something that members of Congress would define,” Chipman said. “The bill to ban ‘assault weapons’ is dozens of pages long. There’s no way I could define it in 30 seconds.”

“You’re going to run this agency and you don’t have a definition of ‘assault weapon’?” Senator John Kennedy (R., La.) asked. When Chipman again refused to answer, Kennedy said he couldn’t vote for him.

“If you won’t answer my question, how can I vote for you?” Kennedy said. “I’m done, Mr. Chairman. I don’t think I’m going to get an answer.”

Republican senators also directed their ire at Chipman for a series of controversial remarks he made after leaving the ATF and was employed by various gun-control organizations. During an appearance on Cheddar in April 2020, Chipman mocked new gun owners as hapless and paranoid.

“Most of the new buyers who went out to the gun store and bought a gun have no training whatsoever,” Chipman told the news network. “In their mind, they might be competent, they might think they’re die-hard and ready to go, but unfortunately they’re more like Tiger King. They’re putting themselves and their families in danger.”

Senator Mike Lee (R., Utah) slammed Chipman for his attitude towards new gun owners, many of whom are minorities, Lee pointed out.

“It concerns me that you, as the nominee to be the director of the ATF, would have such a flippant and, if I may say so, utterly condescending attitude towards first-time gun owners in this country,” he said. “This is a troubling, flippant attitude for somebody who is going to head this agency. Why would you choose to insult so many of your fellow Americans with a statement like this?”

Chipman said his comments were “misunderstood and taken out of context” but apologized for not speaking clearly.

“What I was trying to use is self-deprecating humor. The person who had a gun stored behind his tuna and beef jerky was me,” he said. “I’m sorry for any confusion I made when I was trying to point out the fact that sometimes bringing a gun into your home, if you’re untrained, is a particularly dangerous thing to do.”

Lee did not believe his explanation and he was concerned about that statement in connection with other heated rhetoric he’s used over the years. He cited Chipman’s public opposition to a bill that would have removed silencers from the NFA but retained the requirement that buyers pass a background check. Proponents, including Lee, argued the silencers, often referred to as sound suppressors, protect a shooter’s hearing while Chipman argued there was no viable reason to remove the restrictions placed on the devices.

“The only people that benefit from this bill are gun lobbyists and criminals who want easier access to deadly weapons,” Chipman said in opposition to the bill.

When Lee asked if he stood by that statement, Chipman did not answer directly but said he was trying to “contrast the fact that silencers are legal” and “those that want to buy silencers to protect their hearing, there’s a method to do that.” But it shouldn’t be made easier, he argued.

“That’s not what you said. That’s not what you said at all,” Lee said. “You’re not going to spit downwind and tell us it’s raining.”

Chipman began the hearing by apologizing for lying in a 2019 Reddit post about helicopters being “shot down” during the Waco shootout. When given a chance to clarify his remarks he blamed the quick nature of the social media site’s question and answer format.

“Reddit is one of those things where people fire questions at you and you have to type very fast,” he said about the comments. “I could’ve done a better job of describing them as being forced down because of the gunfire as opposed to shot down which might have left the impression they were blown out of the sky which they were not. I regret that confusion that I added.”

Senator Lee said he was “very concerned” somebody with Chipman’s history of making “inflammatory statements” about gun owners was being considered to head the regulatory agency in charge of enforcing gun laws. However, Chipman tried to distinguish comments he made as a gun-control activist from how he would operate as the director of the ATF. He said he would not try to change or enact gun laws and focus instead on enforcing ones already on the books.

“My leadership mission will be to sharpen ATF’s focus while striving to prevent more violent crimes from occurring in the first place,” he said.

When asked if he agrees with the interpretation by his current employer, the gun-control group Giffords, that the Second Amendment does not protect an individual right to keep and bear arms, he said he did not.

“I’m a gun owner,” Chipman said. “I respect that the Supreme Court has recognized this right and if ATF director, I will ensure to uphold that right.”

But he also said he believed Congress has expansive power to regulate gun ownership and should use it to further restrict the ownership of some of the most popular guns in America.

“I think it is well within the powers of Congress to balance the rights we have under the Constitution and the responsibility as a nation to keep us safe,” Chipman said.