Hillary Clinton: Biden 'should not concede under any circumstances'

Former Secretary of State Hillary ClintonHillary Diane Rodham ClintonAttorney indicted on charge of lying to FBI as part of Durham investigation Durham seeking indictment of lawyer with ties to Democrats: reports Paul Ryan researched narcissistic personality disorder after Trump win: book MORE said in a new interview that Democratic presidential nominee Joe BidenJoe BidenTrump endorses challenger in Michigan AG race On The Money: Democrats get to the hard part Health Care — GOP attorneys general warn of legal battle over Biden's vaccine mandate MORE "should not concede under any circumstances" because she believes the final results in November's election are "going to drag out" due to mail-in voting.

"Joe Biden should not concede under any circumstances because I think this is going to drag out, and eventually, I do believe he will win if we don't give an inch and if we are as focused and relentless as the other side is," Clinton told former aide Jennifer Palmieri on Showtime's "The Circus."

"I think that [Republicans] have a couple of scenarios that they are looking toward. One is messing up absentee balloting. They believe that helps them so that they then get maybe a narrow advantage in the Electoral College on Election Day," Clinton, the 2016 Democratic nominee, alleged. "So we've got to have a massive legal operation, and I know the Biden campaign is working on that."

In a surprise appearance at the Republican National Convention on Monday, President TrumpDonald TrumpOhio Republican who voted to impeach Trump says he won't seek reelection Youngkin breaks with Trump on whether Democrats will cheat in the Virginia governor's race Trump endorses challenger in Michigan AG race MORE told delegates that expansion of access to mail-in voting was politically driven.

"What they’re doing is using COVID to steal an election," Trump argued. "They’re using COVID to defraud the American people, all of our people, of a fair and free election. We can’t do that."

Many political observers have said it is unlikely a winner will be able to be declared on Election Day due to the delays that come with mail-in voting.