This just in: Thomas Mulcair is a citizen of France!

Actually, it isn't "just in" at all. But the NDP Leader, who leads in the polls and who could well be prime minister by November, is under new and intense scrutiny, as he should be.

Provided, of course, we don't take any of this seriously.

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The latest revelation-that-isn't comes from Maclean's, which reported Monday that Mr. Mulcair, after quitting the Quebec Liberals, flirted with joining the federal Conservatives in 2007 before settling instead on the NDP.

Mr. Mulcair turned down the Tories, former Conservative aide Dimitri Soudas stated, because the party could only offer a $180,000 salary, and Mr. Mulcair demanded $300,000.

Not so, said Mr. Mulcair, the talks fell through when it became clear the Conservatives had no intention of honouring Canada's commitment under the Kyoto accord on global warming. Money had nothing to do with it. He never even talked to Mr. Soudas.

Which is true? Well, just ask yourself: Why would Thomas Mulcair walk away from the Conservatives because the money wasn't good enough, and then join the NDP?

The news might actually reassure some voters. If Mr. Mulcair was prepared to consider joining the Tories, how scary can he be on economic issues?

Mr. Mulcair's past flirtation with the Conservatives has been previously reported, but most people paid little attention, because he was back in third place in the polls. Now that he leads those polls, he is rightly subject to increased scrutiny.

So expect to see someone dredge up Mr. Mulcair's citizenship again. The NDP Leader met his wife Catherine when they were both teenagers, and she was visiting from France. After they married, Mr. Mulcair acquired French citizenship.

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Back in 2012, Stephen Harper publicly questioned whether the prime minister of Canada should have dual citizenship. The late Jack Layton, when he was NDP leader, asked the same question about former Liberal leader Stéphane Dion. (Mr. Dion also has French citizenship.) Most people, in a country with millions of citizens who were born overseas, will shrug.

Voters don't know Thomas Mulcair very well, so these stories on his background have some limited value.

Far more important, though, is whether Mr. Mulcair can be trusted to lead the country. It doesn't matter so much that he flubbed a question, recently, on the corporate tax rate. It does matter that he wants to hike those taxes, which could lead to lost investment and jobs.

He appears to care more about global warming than about saving and creating jobs in the petroleum sector. He is lukewarm on trade with Europe, and would rather protect the dairy industry than sign the ambitious Trans Pacific Partnership.

His reluctance to support coalition efforts to contain Islamic State in Iraq brings his foreign policy priorities into question. Who would you rather see representing Canada at the G7: Thomas Mulcair, Stephen Harper or Justin Trudeau? That's a fair question.

During the 2008 Democratic primaries, the Hillary Clinton campaign ran a powerful ad. "It's three a.m. and your children are safe and asleep," the narrator declared. "But there's a phone in the White House, and it's ringing. Something is happening in the world … Who do you want answering the phone?"

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As it turned out, voters trusted Barack Obama to take the call. But now voters in Canada must ask themselves the same question: Do they trust Thomas Mulcair to make that sudden, difficult middle-of-the-night decision? Do they trust Justin Trudeau? Or do they prefer to stick with Stephen Harper?

That's what really matters. The rest is inside baseball.