Donald Trump and Hillary Clinton take the stage Wednesday evening in Las Vegas for the third and final presidential debate — what could be one of the last opportunities for Trump to save his floundering campaign.
Clinton leads her Republican opponent by a healthy margin in most national polls, and appears poised to capture many of the decisive battleground states in the November election.
The two previous debates were bruising affairs that generated many more headlines from the candidates' attacks on each other than from any policy discussion.
Many pundits said the first debate went poorly for Trump, who elicited laughter when said he has a "much better temperament" than Clinton. The New York businessman later claimed he held back on making "inappropriate" comments about Bill Clinton. During that first faceoff, the Democratic nominee slammed Trump for perpetuating a false claim that President Barack Obama was not born in the United States.
The second debate came days after the release of a 2005 video featuring Trump bragging about groping women. Although some prominent Republicans called for Trump to drop out of the race because of the video, he apologized for his comments and counter-punched with personal attacks against Clinton on the debate stage.
But in the week and a half since then, Trump has seen a blistering series of allegations from women that he had made unwanted sexual advances. In response, the Republican nominee has ratcheted up his rhetoric that the media, and even fellow Republicans, are working against him in a coordinated conspiracy. He's also suggested that the election could be "stolen" from him as the result of "large scale voter fraud" — even though there's considerable evidence that voter fraud is a nearly nonexistent problem in the country.
Many pundits, strategists and politicians have charged that Trump's repeated claims of a "rigged" election are an attempt to lay the groundwork for post-election excuses.
As for Clinton, her campaign has also been hit by a barrage of negative headlines. Earlier this week, the FBI released its latest cache of notes on its investigation into her use of a private email server during her tenure at secretary of state. That trove included allegations of a "quid pro quo" about
lowering the classification of an email in return for State Department approval of more FBI agents abroad. Representatives for both the FBI and State Department have denied that such a deal had occurred.
Clinton has also seen a steady stream of negative news from documents published by WikiLeaks that were purportedly the emails of her campaign chairman, John Podesta. Those supposed leaks (the veracity of which have not been officially confirmed) include revelations about the Clinton Foundation, Clinton's speeches to Wall Street and suspicious dealings with a Democratic National Committee official.
The third debate, which starts at 9 p.m. ET, is being moderated by Chris Wallace of Fox News.
—CNBC's Christine Wang contributed to this report.
For full live coverage of the debate, go to CNBC.com starting at 9 p.m. ET Wednesday.