Las Vegas (CNN)For Hillary Clinton and Donald Trump, it's time to begin the closing arguments.
Both nominees enter Wednesday's presidential debate -- the final showdown of the election season -- with historically high unfavorability ratings, and need to convince undecided voters why the country would be worse off with their opponent in the White House.
Trump enters the match-up in his weakest position yet in national polls and is losing ground in key battleground states. And he is making perhaps his most outlandish argument yet -- that the 2016 election is rigged to help Clinton win. Clinton, meanwhile, will have a fresh set of questions to answer around newly released hacked emails and fresh revelations about her use of a private email server at the State Department.
If the last two debates are any indication, Wednesday night promises to be contentious, theatrical, and unpredictable. Here's what to watch: