Here are five things Trump and Clinton need to do in Wednesday's debate.

Donald Trump:

1. Decide whether to be the "issues" Trump or the "take-no-prisoners" Trump

During the campaign, Trump has oscillated between issue-oriented speeches and slam-bang rallies in which he accuses Hillary and Bill Clinton of all kinds of misbehavior. In recent days, he's ramped up charges that critics, including the media, are trying to "rig" the election against him. The more aggressive Trump showed up at the last debate — along with a few of Bill Clinton's past accusers, invited by the Trump campaign — in St. Louis on Oct. 9, generating what was perhaps the nastiest debate in presidential history. Will the showdown in Las Vegas be worse?

2. Address women directly

Trump will likely be called upon to defend himself against claims by more than a dozen women who have accused him of unwanted sexual advances. There's also the recording made public earlier this month in which Trump talks about how he can grab, grope and kiss women because he is a celebrity. As a result, the Republican nominee's approval ratings with women — never high to begin with — have dipped even more in recent days. Trump needs to use this debate to improve his standing among female voters, who make up more than half the electorate. That includes female Republicans, who could put traditionally red states in play for Clinton if they defect in significant enough numbers.

3. Act presidential

This is Trump's last chance to pass the presidential threshold test in front of a television audience of tens of millions. He must prove he has the knowledge and the temperament to be president and commander in chief, attributes voters have expressed doubts about after the first two debates. The New York businessman has never held public office, and his lack of familiarity with the challenges of the job have become apparent. One of the scheduled debate topics is "fitness to be president," and Trump needs to rise to that challenge.

4. It's not just about her

Trump needs to get beyond attacking Clinton (and her husband). He needs to talk about what he would do as president and what kind of vision he would bring to the presidency. Look for Trump to talk more about issues, such as his new proposed political ethics reforms. Another scheduled debate topic should be in Trump's wheelhouse: immigration, which didn't surface during the first two sessions with Clinton.

5. Avoid a big blow-up

Trump has expressed deep anger on the campaign as the allegations against him have mounted. They don't make much difference with his supporters, but angry outbursts would not play well on a nationally televised debate stage. Trump needs to be cool, calm and collected as he debates the Democrat seeking to be the first female president, a rival who has questioned the Republican's very stability.

Hillary Clinton:

1. The WikiLeaks cloud

There’s been a stream of embarrassing email exchanges between Podesta and Clinton aides made public through the website WikiLeaks. The campaign argues the hacked communications are being released via a Russian government attempt to influence the U.S. election, but they're not denying the veracity of many of them.

They include exchanges showing internal concerns about everything from Clinton's ability to convey sincerity to her use of a private email server.

While there is no single smoking gun, collectively the messages risk painting a cynical view of her campaign that could endure beyond the election. Clinton must have an effective rejoinder that doesn’t revolve solely around blaming the Russians.

2. Buck up liberals

The biggest risk for Clinton is a demoralized Democratic base, mainly among liberals whose first choice was Sen. Bernie Sanders of Vermont. She needs to reactivate President Obama’s winning coalition that relied on strong turnout among young people and African Americans.

Trashing Trump probably isn’t enough, and time is running out.

Some WikiLeaks exchanges underscore just how significant a struggle this has been for her all along. In one exchange shortly after she lost New Hampshire to Sanders, Joel Benenson, the campaign’s chief strategist, expressed uncertainty about what “she believes or wants her core message to be?”

3. Let Trump be Trump

Since the first debate on Sept. 26 at Hofstra University, Clinton’s largely stayed out of the spotlight as Trump’s campaign reels from accusations about his treatment of women, including numerous allegations of sexual misconduct.

She’s kept a lighter campaign schedule than Trump, opting for private fundraisers and intense debate preparations, while allegations about Trump’s past behavior — and his response to them — have dominated the headlines.

In an election where the public is overwhelmingly negative about both of their options, the outcome appears to hinge on which candidate proves to be the least unpopular choice. In that context, it makes sense for Clinton to pull her punches if it looks like Trump is continuing to drive up his own negative ratings.

4. Sharpen answer on trade

Of all the WikiLeaks emails, the most politically damaging may be an excerpt of a 2013 Clinton speech to a Brazilian bank in which she said her “dream” is “a hemispheric common market, with open trade and open borders.”

The transcripts of Clinton’s paid Wall Street speeches have been a flashpoint since the primaries, and this excerpt probably shows why she’s kept them under wraps.

The statement risks inflaming both her liberal base — by pining for the same free-trade deals they’ve railed against — and Trump’s voters, by calling for a freewheeling system of open immigration. They also stand in contrast to the positions she’s taken publicly in this campaign, as Clinton’s insisted she’s a critic of trade deals that have hurt U.S. workers and denied she is for totally open borders.

The debate moderator, Fox News’ Chris Wallace, is almost guaranteed to ask her about this.

5. Be ready, literally, for anything

Based on numerous polls, Trump is trailing Clinton by margins that have proved to be historically difficult to recover from.

During the last debate, Trump invited women who’ve accused Bill Clinton of sexual assault to the debate hall to try to confront the former president and in order to create an embarrassing spectacle tarnishing her image.

With Trump already potentially positioning himself for a defeat, arguing the system is “rigged,” it’s anyone’s guess as to what kind of opposition research he’ll throw out or what kind of made-for-TV spectacle he’ll orchestrate.