Here we go again: Trump, Biden reprise debate duel

Television viewers across the United States and Canada might well wonder tonight why living room couches don't come with seat belts.

After last month's interruptive, insult-riddled debate performance against Joe Biden, Donald Trump has a chance to redeem himself — though observers don't expect him to try.

Instead, they're bracing for another show of vintage Trump, one in which he'll seek to be heard even in spite of his muted microphone.

The Commission on Presidential Debates will be cutting off the opposing mic during two-minute opening statements before each 15-minute segment.

Tonight's debate, hosted by Belmont University in Tennessee, will be moderated by NBC News correspondent Kristen Welker.

Topics will include American families, race relations, climate change, national security and leadership.

Trump's campaign manager Bill Stepien called the decision to cut off microphones an attempt by the commission "to provide advantage to their favoured candidate."

In fact, the commission said in a statement this week, it's designed to level the playing field for the two candidates.

"One may think they go too far, and one may think they do not go far enough," the statement said.

"We are comfortable these actions strike the right balance, and that they are in the best interest of the American people, for whom these debates are held."

During last month's clash in Ohio, Trump interrupted, antagonized and irritated his Democratic rival from the outset, vexing moderator Chris Wallace and eliciting an exasperated plea for order from Biden himself: "Will you shut up, man?"

And that was only the first 15 minutes.

It was hardly the most cutting insult of the night — Biden called Trump a "clown" and America's worst-ever president, while Trump branded his rival a drug-addled socialist and the Biden family a criminal enterprise.

But the "shut up" line emerged as the sound bite of the night, a fact that experts say offers clues into Biden's best strategy.

"My advice to Biden would be to do exactly that — have a few pithy one-liners. But they also have to be presidential," said Will Stewart, a former Progressive Conservative operative who's now a senior vice-president with Hill+Knowlton Strategies in Toronto.

"I think 'Shut up, man' was the wrong approach. I think it was tone-deaf; it sank to Donald Trump's level. It's also not presidential. And I don't care if you don't like Donald Trump, you respect the office of president."

This time, Biden would do well to ignore the president's "buzz saw" approach, or at least find a way to short-circuit it, said Stewart, who is no stranger to the rituals of debate prep.

As for Trump, the mission — should he choose to accept it — is a relatively easy and simple one, say veterans of debate strategy: stop being such a jerk.

Performing better than the public expects, which is Job 1 in a political debate, ought to be easy when the expectations of Trump likely couldn't sink lower.

On that, the experts agree. Also on this: don't hold your breath.

"I expect to see Trump very aggressive, fighting like someone who is behind in the polls and knows he needs to make up ground," said Gerald Butts, Prime Minister Justin Trudeau's former principal secretary.