How Trump can win the 3rd debate and regain momentum

History and political scientists tell us that 20 days before election day is usually too late to turn things around in a presidential contest. But this isn't a usual election. And Wednesday night's third and final debate between Donald Trump and Hillary Clinton might provide Trump with a legitimate chance to get a winning message across to the public even at this late stage in the game. Luckily for Trump, he's starting to do that even as the pundits and news media don't seem to quite see it yet.

A look at the polls tells us Trump really needs to change the momentum in this election and thus, this debate is more crucial for him. Trump blew through the primaries and looked like he had a great chance to win the White House with his simple "Make America Great Again" message. It was a tailor-made slogan that effectively meant different good things to a lot of different people. But it hasn't been enough to get him over the finish line, especially in light of the "Access Hollywood" tape leak and the sexual assault allegations against him.

At this point, Trump is unlikely to come up with another rallying cry as good as "Make America Great Again," but he's coming close with a phrase that's starting to appear on his Twitter feed: "Drain the Swamp."

That's a pithy way to incorporate all the outrage over the Clinton Wikileaks revelations, the progressive movement's anger over what they see as a corrupt economy and government, and all the usual anti-Washington sentiment in America. It's what they used to call a "reform movement" campaign that can only plausibly be led by an outsider.

Just Tuesday, he gave new definition to that reform movement by promising to propose a Constitutional amendment for Congressional term limits if he's elected. That's a winning message for him that he should repeat at the debate again and again, because Congressional term limits have always been popular in the polls and term limits fits so perfectly into a "drain the swamp" message.

And yes, this call for reform includes the controversial "election is rigged" message that the intelligentsia from President Obama to even some Republican strategists are disparaging. They're half right, because Trump's best message on the campaign trail and in the debate will be to focus on an overall system he thinks is rigged against most Americans, not just election-rigging.

"The best advice and the top goal for Trump Wednesday night might simply be to behave."

How do we know this general "us vs. them/the system is rigged" message can work? Because it worked beyond all expectations for Senator Bernie Sanders in his improbable near win of the Democratic primary season. The fact that so many relatively well-off Americans and their young adult children supported the Sanders movement proves you don't have to actually be poor or struggling financially to believe our American system has become unfair.

This is his last opportunity to remind the voters that both the Democratic and Republican Party establishments are against him. And he needs to use that establishment opposition to connect with that growing number of Americans who believe things really are stacked against them too. Frankly if he doesn't take the chance to do this in the final debate, then he really doesn't have what it takes to deserve to win the election anyway.

The final debate has presented Hillary Clinton with an imperative as well. Sure, she may win this election even if all she does at the debate is smile and say her usual list of platitudes. But this week's new NBC/Wall Street Journal poll showing that younger people and African Americans are the most likely not to vote at all should be setting off some alarm bells for her.

Several pollsters have surmised that Clinton needs a decent African American turnout to win key states like Florida. And Trump's relative weakness among younger voters means things wouldn't bode well for Clinton either if too many of them stay home on Election Day. Why is turnout suddenly an issue in the election?

It's simple: Negative campaigning. The one thing that drives voter turnout down is negative campaigning. And in a year where both candidates have been in the 60 percent negative approval rating range, it's a wonder we aren't expecting the worst voter turnout of all time.

With many battleground state polls still bouncing all over the place, Clinton needs to take a small risk and find one issue or policy to pound time and again in the debate. It should have nothing to do with Trump and it shouldn't appear negative in any way.

Her best choice could be the increased child tax credit she's proposing now and to somehow make it sound like that break will be a panacea for voters of all kinds. But whatever she chooses, it's past time for her to project some kind of agenda that transcends just the fact that she's not Donald Trump.

Of course, all of this is best case scenario speculation. Both of the two previous debates quickly descended into low-brow and shallow affairs. If moderator Chris Wallace loses control of the affair like the moderators did in the first two debates, neither Trump nor Clinton will be able to accomplish anything. In that likely scenario, the advantage would go to Clinton.

That's why the best advice and the top goal for Trump Wednesday night might simply be to behave.

Commentary by Jake Novak, senior columnist. Follow him on Twitter @jakejakeny.

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