While the biggest attraction during the presidential debate tonight will be the two candidates on stage, at least some attention will likely be paid to those in the audience. More than 67 million people watched the first debate between Barack Obama and Mitt Romney in 2012.
It will take place at Hofstra University, Hempstead, and is being broadcast live on ABC News in the States.
Trump will try to present as one who can make quick decisions, doesn't waffle and isn't intellectual, but is a "true American" - and it's this that Clinton will have to undermine by tripping him up, said Hoadley.
Clinton, looking to become the first female USA president, is the more seasoned debater, having gone head-to-head against political opponents over the last 16 years, including Obama in the Democratic presidential nominating contest she lost to him in 2008.
Fortune magazine's tipped it to be the most-watched presidential debate in history, and as popular as the Superbowl.
Hillary Clinton's campaign manager, Robby Mook, says debate moderators should correct any false statements by Trump so Clinton can use her time discussing her plans instead of correcting her rival. Investigators concluded that her actions were "extremely careless", but not warranting of criminal charges.
Clinton's camp has done its best to raise the bar for Trump, and in television interviews on Monday both campaigns tried to frame expectations.
NBC Nightly News Anchor Lester Holt.
The two candidates are almost tied in recent polls, and each faces unique challenges headed into the first of three scheduled presidential debates.
SEGMENT FORMAT: Each segment will begin with a question.
FiveThirtyEight: Clinton's chance of winning is now at 51.5 percent, with Trump closing in at 48.5 percent.
The current record for a televised presidential debate is 80.6 million viewers, set by the 1980 encounter between the Democratic incumbent, Jimmy Carter, and his Republican challenger, former California governor Ronald Reagan. "So I think there's huge risk if he goes after her in that fashion that a lot of in particular women will say, 'holy smokes that's out of bounds'".
Even Cuban believes that Trump stands to win in the long-term just by being a presidential nominee should he lose the election, which Cuban claims would be Trump's "dream scenario".
9 p.m. ET. The debate will last 90 minutes with no commercial breaks.
The themes of Monday's debate - the first of three between Trump and Clinton - will focus on "America's Direction", "Achieving Prosperity" and "Securing America".
Hillary Clinton is experienced when it comes to debates. That leaves about 10 minutes for back-and-forth debate in each segment.
They're going to make America debate - again. A month ago, Monmouth showed Clinton leading Trump by seven.