One of the nicest things about living in Canada is that we don't do politics like Americans.

For years, I've been saying that one of the worst ideas our friends down south ever had was the system of voters registering party affiliation. Republican, Democrat, even registering as an independent is a deliberate political choice.

The problem with that system is that once people choose a political identity, well, they've pinned themselves down. They've picked their team, and they become deeply entrenched in their choice.

This is one reason for the staggering political polarization in the U.S., where elections are either landslides (because states are divided 55-45 between the two parties) or razor-thin (where it's 51-49 or 50-50 in terms of registered voters).

Meanwhile, in Canada, we have no such system of political registration. To become a member of most political parties, you actually have to buy a membership, which also means the party has your address. For reasons of frugality (or of not wanting to get a flood of emails and flyers begging for more donations) many Canadians shake their heads and decide they'll just pick who they're voting for without being an official member of a party.

And that's why Canadians can do something that eludes Americans – they can change their minds, sometimes en masse.

A string of recent polls have found that the Liberals have regained significant strength, after years of being in the doldrums.

Conservative leader Pierre Poilievre, who has spent the last year yelling carbon tax slogans and mentally measuring Rideau Cottage for new drapes, now might actually have a fight on his hands.

Why the sudden change in political opinion?

Remember why Prime Minister Justin Trudeau and the Liberals were in deep, Kim Campbell's Tories-level trouble in the first place. A long string of conflict of interest scandals. Failure to respond adequately to a long-simmering housing crisis that, because of dramatic increases in immigration and temporary foreign residents, looked to be at least partly of their own making. And of course, inflation, which has made everyone grumpy.

Poilievre was poised to capitalize on simply not being Trudeau.

But then Trudeau (finally, at long last) announced his departure. And President Donald Trump began talking about annexing Canada, and threatening devastating tariffs.

The housing market may be a real problem, inflation has nibbled away at our spending power, but the prospect of a sudden recession, caused by a bloviating bully from south of the border, refocused voters' priorities.

Liberal leadership candidate Mark Carney is now as trusted – if not more, depending on which poll you read – as Poilievre to take on Trump. And that's the key issue on voters' minds right now.

Of course, this being Canada, that could all change again. Carney could lose the leadership race, or if he wins, could prove an inept campaigner in a general election. Poilievre could brush up on his Trump-fighting bona fides. And based on what they see over the next three months or so, Canadians will make their choice at the polls.

Being free of pre-conceived allegiances allows Canadian democracy more flexibility than our erstwhile American friends.