Debate Day Preparation: how Clinton & Trump are getting ready to take the national stage

It may seem like the Presidential debates date back to the days of our Founding Fathers. But really, they've only been around since 1960, when TV's were first invented.

While there's nothing in the Constitution saying the Presidential candidates have to debate one another, the audiences are often too big to pass up. 67.2 million people watched the first debate between President Obama and Mitt Romney in 2012. Analysts predict the first showdown between Hillary Clinton and Donald Trump could top 80 million.

The country can expect two very different candidates onstage. Clinton in a debate is all about what's she's done, while Trump is about simple, sweeping promises. That's according to Brett O'Donnell, a long-time debate coach for GOP candidates, who talked about their contrasting styles. O'Donnell explains, "He (Trump) talks in these big, giant terms. She doesn't tend to do that, and I think that it puts him at an advantage because he understands well the dynamic of television." O'Donnell said that Clinton's biggest flaw is being defensive and that Trump's biggest shortcoming is name-calling.

A new poll shows Trump and Clinton are running neck-and-neck ahead of the showdown. The ABC News-Washington Post poll shows Clinton two points ahead of Trump, with Libertarian Gary Johnson and Green Party nominee Jill Stein polling in the single digits. Clinton's lead in the same poll has shrunk eight points since early August.