The majority of Sunday night's Democratic debate between former Vice President Joe Biden and Sen. Bernie Sanders was spent discussing the coronavirus pandemic, contrasting how the two candidates would handle such a situation versus the Trump administration. But about an hour in, Sanders began targeting key differences between his and Biden's voting record—including the anti-LGBTQ Defense of Marriage Act (DOMA).

Biden and Sanders began by sparring over a 2005 bankruptcy bill that the former supported, defending his decision to do so by noting that "an overwhelming majority" in the Senate voted for it. He also stated his support for Sen. Elizabeth Warren's bankruptcy plan to repeal some of the language in that bill.

Sanders pointed out that he voted against it as a member of the House, before highlighting their records on other issues. "Your support for legislation regarding gay communities, and the so-called Defense of Marriage Act—you remember that bill, right?" the Vermont senator asked.

"I sure do," Biden said.

"It was—you know, gay marriage today is considered a little bit differently than it was 25 years ago. I remember that vote, it was a very hard vote. I voted against the Defense of Marriage Act, you voted for it," Sanders said.

The senator went on to point to his early support for free college and a $15-an-hour minimum wage, as well as his votes against the Iraq War, NAFTA, and the Hyde Amendment.

Biden shot back by criticizing Sanders for voting against the Brady Bill five times, as well as voting against having the right to sue gun manufacturers.

"He says it's a mistake now," Biden said. "I'm prepared to accept he says it's a mistake. The question is, what do we do from this point on?"

"And by the way, I might add, I'm the first person to go on national television in any administration and say I supported gay marriage... and that started a ripple effect," he added.

This was not the first time Sanders went after Biden for his 1996 DOMA vote, having made criticisms of the former VP's social record a more prominent part of his campaign in recent weeks. Sanders has also been critical of Biden's vote for the “Don't Ask, Don't Tell" amendment as part of a larger defense bill, which the Biden camp was quick to note came around the same time Biden voted to remove anti-gay language from the 1993 Defense Authorization bill.

Arizona, Florida, Illinois, and Ohio will all hold primary elections on Tuesday.