A spokeswoman for Sen. Bernie Sanders’ (I-VT) presidential campaign told Hill.TV Thursday that other candidates are going to “have to answer for their histories.”

Sanders spokeswoman Briahna Joy Gray spoke to the Hill.TV ahead of Thursday night’s Democrat presidential debate in Houston, Texas, and told the outlet that Sanders’ competitors need to address the positions they have held in the past.

“A lot of candidates are going to have to answer for their histories — both in office and before they joined political office,” Gray said.

Sanders has largely refused to get into the political mud with his competitors, overtly refusing to criticize Sen. Elizabeth Warren (D-MA), who is in many ways his ideological ally.

Gray signaled that she is not worried about candidates questioning Sanders’ past, suggesting that his record speaks for itself.

“We have a candidate who has been in office so, so long and yet at the same time doesn’t have all of those foibles,” she told the outlet.

Sanders has yet to stress the need for launching attacks at fellow candidates. During the second presidential debate, Sanders teamed up with Warren, defending their radical policies from more “moderate” Democrats like former Rep. John Delaney (D-MD). However, the “moderate” Democrats who sparked the majority of the squabbles were not present during Thursday evening’s debate. Sanders, though, appeared to make a distinction between himself and Joe Biden (D), noting their policy differences on Medicare for All and trade. Sanders also grilled Biden over his past support for the Iraq War.

“You [Biden] talked about the big mistake in Iraq and the surge. The truth is, the big mistake, the huge mistake, and one of the big differences between you and me, I never believed what Cheney and Bush said about Iraq,” Sanders said, to which Biden agreed.

“You’re right,” Biden said.

“I voted against the war in Iraq and helped lead the opposition. And it’s sad to say — I mean, I, kind of, you know, had the feeling that there would be massive destabilization in that area if we went into that war,” Sanders added: