WASHINGTON — Hillary Clinton’s main job in Wednesday’s third and final debate with Donald Trump will be to defend herself about her use of a private email server, the Clinton Foundation and her Wall Street speeches.

If Trump comes to the stage at the University of Nevada in Las Vegas prepared and disciplined — which he lacked in their two previous debates — he may be able to slow down Clinton’s rise in the polls.

Clinton is ahead in almost every key battleground state poll. Trump has only a tiny or perhaps no path to winning the 270 electoral votes needed to claim the White House.

With early voting already starting and just a few weeks before
Election Day, this third debate is the last time Trump is guaranteed a massive audience to woo undecided voters.

Trump has disdained prep — something that Clinton does with intensity — and may not be able to leverage new opportunities that have come up since their second debate at Washington University in St. Louis on Oct. 9.

OPINION

The debate takes place with Trump on the defensive over sexual misconduct after allegations by women surfacing in the past few days. Trump’s sleazy behavior is going to be a major part of the debate.

But the debate also comes as Clinton’s greatest vulnerabilities are even more exposed and raw, magnifying her greatest problem: Voters do not trust her.

The stolen WikiLeaks emails with Clinton’s speech drafts have been dribbling out in the past few days. On Monday, interviews she had with FBI officials over her private email server were released.

That raised the question of whether a top State Department official was pressured to change the security classification of one of her emails, which the State Department and the Clinton campaign denied.

The anchor is Fox News’ Chris Wallace — the son of “60 Minutes” legend Mike Wallace — who at the beginning of his career reported for WBBM-TV in Chicago. This will be the first time a Fox journalist is moderating a general election debate.

I can’t image that Wallace will not pursue a line of questioning with Clinton over the controversies that have dogged her — and were not dealt with in depth at the two previous debates.

Trump is digging in on his claim, with no evidence, that there is ongoing widespread voter fraud creating a rigged election, assisted by a conspiracy between all media and the Democrats.

If Trump keeps talking about the election being over because the outcome is rigged, he risks making some of his supporters think their votes don’t count, depressing his own vote.

Trump has not made it crystal clear he will accept the balloting results if he decides his defeat was the result of some rigging in the precincts.
On Tuesday, President Barack Obama said “there is no serious person out there who would suggest somehow that you could even rig America’s elections, in part because they’re so decentralized and the numbers of votes involved. There’s no evidence that that has happened in the past, or that there are instances in which that will happen this time.

“And so I’d advise Mr. Trump to stop whining and go try to make his case to get votes,” Obama said.

Clinton has been in practice sessions and off the campaign trail since Friday.

WikiLeaks’ emails posted on Tuesday about Clinton’s debate prep earlier this year and last — when she was battling Bernie Sanders in the primary — provide a rare detailed window into her prep process.

Clinton’s debate team wrestles in internal debates about alternative lines to use. There is gaming out of verbal traps for her to avoid. There are suggestions about how to effectively push back a line of argument. Practices are hours long.

Clinton’s team prepares a “Debate Book” for her to study.

No detail is overlooked. A March 4, 2016, email said: “The yellow highlights on the table of contents are the sections we told her to focus on.”

Clinton prevailed over Trump in the two previous presidential debates. Trump has been mocking Clinton’s prep sessions.

You know what they say about practice . . .