Clinton campaign manager concerned "Trump may lie" during debate

As the two presidential nominees prepare to take the stage Monday night for their highly anticipated first debate, Hillary Clinton’s campaign manager, Robby Mook, talked about what the campaign will be looking for in Trump’s performance.

“We are concerned Trump may lie and throw misinformation out there and that Hillary will have to spend all her time trying to correct the record, rather than about the things she wants to talk about,” Mook told “CBS This Morning” on Monday.

How Monday night’s debate moderator, NBC’s Lester Holt, deal with false statements from the candidates is also something Clinton’s campaign will be watching closely. Mook said the Clinton campaign wants Trump checked by moderators. 

“All that we’re asking is that the record be checked,” Mook said, “and so if Donald Trump lies, which he has repeatedly done in the past, that that be simply checked.”

Clinton has been preparing rigorously for the debate. As CBS News’ Nancy Cordes pointed out, Clinton had only two public events last week, compared to Trump’s nine, so that she could go over briefing books and practice her debating. She’s been preparing for two Donald Trumps, a point Mook also addressed Monday. 

“One of the concerns that voters have about Donald Trump is that is that he doesn’t have the right temperament to be commander-in-chief; he is erratic,” he said. “We don’t know if Trump is going to show up to have a serious discussion of the issues or whether he’s going to bully. We’ve seen him bullying HIllary with some mean tweets the last few days. We just don’t know who will be there.”

Billionaire entrepreneur Mark Cuban, who’s tweaked Trump over Twitter, and who has endorsed Clinton, will be sitting in the front row. Is he there to unnerve Trump?

“That was not the intent,” said Mook, saying that the campaign is “really proud” to have Cuban’s support. “He’s not political, he’s a businessman, has a lot of experience creating jobs...he’s been outspoken and we’re really excited to have him there. He represents the kind of people that are coming to this campaign -- Republicans, Republican-leaning independents who are concerned about Donald Trump’s temperament.”

Clinton and Trump face off Monday night for an uninterrupted 90 minutes at Hofstra University in New York in the first of their three presidential debates of the general election, and it will mark the first time when the two nominees will appear on stage together during this contentious campaign.