After two mass shootings that killed 31 people in Texas and Ohio, Democratic presidential candidate Joe Biden said Monday he would push for a federal buyback program to encourage Americans to give up their military-style weapons and ammunition.

The former vice president said in an interview with CNN that the voluntary weapons buybacks would be in addition to his push for renewing a lapsed federal ban on new manufacturing and sales of such firearms — a prohibition he helped win in 1994 as a senator from Delaware, only to watch it expire a decade later.

He also accused President Donald Trump of “using the language of” white nationalists, including the shooting suspect accused of killing 22 at a Walmart in El Paso, Texas, over the weekend. Yet Biden stopped short of some of his rivals for the 2020 Democratic nomination, including El Paso resident Beto O’Rourke and New Jersey Sen. Cory Booker, by declining to call Trump himself a white supremacist.

“I’m not sure what this guy believes, if he believes anything” other than political “opportunity,” Biden said, before adding that the distinctions ultimately don’t matter.

“Look at the way he talks about Muslims. Look at the way he talks about immigrants. Look at the way he talks about people of color,” Biden told CNN. “He talks about them almost in subhuman terms.”

Biden continued: “We went through this before in the ’20s with the Ku Klux Klan and 50,000 people walking down Pennsylvania Avenue in their hats and robes because they decided they didn’t want Catholics coming into the country. We went through it after the Civil War in terms of the Ku Klux Klan and white supremacy. This is about separating people and the good and bad in his mind.”

That, Biden said, coaxes white supremacists from the shadows of American society.

“This is pure and simple white nationalist terrorism,” Biden said, adding that he supports adopting a federal domestic terrorism law, a move that could give the Justice Department more avenues to investigate and prosecute certain acts.

Trump on Monday called on the nation to condemn white nationalism, but didn’t apologize for his incendiary rhetoric on race, from referring to illegal immigration as an “invasion” to his recent Twitter attacks on black members of Congress. The president mentioned violent video games and mental illness as variables in a consistent wave of mass killings in the Untied States, but said nothing about new bans on the kinds of weapons used in the killings. There is no evidence that playing video games leads to violence, and most people with mental illness are not violent.

When Trump’s nod to video games came up in the CNN interview, host Anderson Cooper noted that Biden was rolling his eyes.

“It’s not healthy to have these games teaching kids this dispassionate notion that you can shoot somebody and just sort of blow their brains out,” Biden said. “But it’s not in and of itself the reason why we have this carnage on our streets.”

Biden is not alone in pushing more restrictive gun laws. There is broad agreement among Democrats on a need to ban the new manufacture and sale of certain military-style weapons and high-capacity ammunition clips, while requiring background checks for all gun sales, including those at gun shows that are now exempt.

Buyback programs have become more frequently mentioned since the latest massacres.

Biden stressed that an “assault weapons ban” would keep the number of weapons in circulation from expanding and that the buyback program would help bring down the current count.

The former vice president said he knew of no “legal way” to compel people who already own such weapons to give them up. But he also argued against the notion that the Second Amendment affords an absolute right to any weapon. “You can’t buy a flamethrower,” he said.

Indeed, the Supreme Court has expressly said that government can regulate firearms.

But Biden said he has no plans to push a national gun registry, like Booker is proposing.

Asked about California Sen. Kamala Harris’ proposals to take executive action to impose tighter gun regulations if Congress doesn’t act, Biden doubled down on the need for legislation, because “the next guy” in the White House can “undo” any executive action — which is what he said Trump did to many of President Barack Obama’s executive orders.