Voters have heard the television ads, the sound bites and the political analysts. Now, they'll get the chance to hear from the candidates themselves.
At 9 p.m., President Bush will debate Sen. John Kerry at the University of Miami in Coral Gables, Fla., in what is expected to be the key turning point in the race for the White House.
The debate, which will air live on all four major television networks, will cover foreign policy and homeland security - areas, polls suggest, in which Bush has a clear advantage over Kerry.
But experts stressed that nothing is set in stone.
"This debate has the potential to be very important," said David Rohde, a professor of political science at Michigan State University. "Kerry has the chance to narrow the gap, even take the lead, or Bush can close the deal."
Coming into the debate, each candidate has been criticized for his approach to public speaking.
Kerry has been described as boorish and "out of touch" with the common man, while Bush is reputed to be down-to-earth but overly simplistic.
Rohde said having both style and substance is important.
"Debate is not a bare recitation of facts, but (the candidates) must create a connection with the audience," he said.