This year, Mr. Trudeau isn’t quite as keen about them. He didn’t show up at a debate organized by Maclean’s magazine and Rogers Communications’ chain of TV stations despite joining it last time. And then came his decision to not make a repeat performance at the Munk Debate on foreign policy.

But, at the same time, Mr. Trudeau isn’t limiting himself to the two official French and English debates. He has also agreed to join one organized by TVA, the French-language broadcaster that won’t air the official French-language debate but which has very significant ratings in vote-rich Quebec.

Peter Donolo, who was the director of communications for the Liberal Prime Minister Jean Chrétien and who helped Mr. Trudeau prepare for the televised debates in 2015, told me recently that it is a political calculation.

“Last time he needed the maximum number of debates, there was no downside,” said Mr. Donolo, who is currently vice chairman at Hill and Knowlton Canada and not involved in the current campaign. “But now the maximum number of debates brings the maximum number of risks for him as the incumbent.”

It’s a risk that Mr. Trudeau’s father addressed 51 years ago during the first debate.

“Some might say there might have been some risks for a prime minister to accept this type of debate,” the elder Mr. Trudeau said in opening remarks. “I rather think that the risk exists if he didn’t accept. Because a democracy is essentially an exchange of ideas between those who govern and those who are governed.”

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