The fact is, the Democratic and Republican presidential nominees usually debate only two or three leading up to each general election. Why assume that in 2020, Trump will agree to even one?

Trump will hold rallies in big venues, drawing upon the perks of the presidency, when possible, for travel and ground support. He will play to his base, as he always has, and he'll rely on wall-to-wall coverage from his friends at Fox News. Vice President Mike Pence will do much of the heavy lifting in smaller markets, as will Donald Trump Jr. and his girlfriend, Kimberly Guilfoyle, a former Fox News host. The two Trumps will be relentless in skewering the Democratic nominee, but it won't happen on a debate stage, and it won't be face-to-face.

Thus, the question for Democrats isn't so much "Who can take it to Trump?" but rather, who will provide the least ammunition for Trump's attack machine? (Hint: If you're a self-described "socialist," or if you favor a health care plan that puts insurance companies out of business, or if you advocate decriminalizing illegal border crossings, or if you make so many gaffes that reciting them at a GOP rally makes a good comedy routine, then Trump is certain to take it to you.)

For all the Democrats, and particularly in Thursday night's debate featuring the top 10 candidates, there's a temptation to evaluate them at least in part on a take-it-to-Trump scale. Back in June, California Sen. Kamala Harris won praise — and a brief polling boost — when she took aim at Biden over his record on busing. If she could spar with the former vice president, the idea was, then she might have what it takes to battle Trump. In July, it was New Jersey Sen. Cory Booker's chance to face off with Biden over his positions on criminal justice. And Booker, too, was credited for showing the kind of toughness that many seem to think will be essential in defeating Trump.

It's a meaningless metric; tough stuff is a distraction.

Yes, the Democratic hopefuls need to find a way to stand out on the debate stage, especially with 10 candidates competing to get a word in. Minnesota Sen. Amy Klobuchar and Mayor Pete Buttigieg of South Bend, Indiana, are two who have consistently shown restraint while being sharp and articulate on the issues. But raising their profiles without raising their voices is no easy task.

In the summer's first debates, moderators from NBC News and CNN seemed eager to draw the candidates into personal confrontations rather than focus on policy differences. ABC News has four moderators in Houston, and viewers will be best served if the questions are more substantive and less provocative.

A year from now, if Trump agrees to one, two or even three debates, and he might if he's losing badly, the Democrat standing across from him will have little to gain by stooping to Trump's level and talking tough. Victory will go to whoever is best able to articulate the failures of the Trump administration and the promise of a return to civility, compassion and, yes, progressiveness, in the White House.

In my view, President Barack Obama remains the ideal candidate, so it's fair to ask: What would Barack do? Well, he wouldn't go toe-to-toe or tit-for-tat with a bully like Trump, that's for sure. He'd kill with kindness.

In a speech in 2012, Trump said: "One of the things you should do, in terms of success: If somebody hits you, you've got to hit them back five times harder than they ever thought possible."

As the 2020 primary and caucus voting draws nearer, I believe voters will reject not only Trump but also his combative style. We don't need someone to take it to Trump. The nation merely needs someone ready to take it to a better place.

(c) Peter Funt. This column originally appeared in USA Today.