By the by(elections) ...

Today, Canadians in four ridings are voting for new Members of Parliament in what is being billed as a significant test for both Stephen Harper and Stephane Dion.

In the two by-elections in Toronto, both Martha Hall Findlay and Bob Rae are expected to score easy victories in safe Liberal seats. Both former leadership rivals to Dion, their presence on the parliamentary "dream team" could be seen both as a boon to the leader (who gains able representatives for Question Period, particularly Mr. Rae, who is known to be an able debater) and a potential challenge (could they outshine him as other MPs such as Michael Ignatieff have done?). But on the whole, I expect their presence to bolster the front lines and, hopefully for the Liberals, their party's fortunes.

The other two races out west in Saskatchewan and B.C., however, may prove to be a little dicier. Dion needs to win both to silence his critics (for now). A loss in SK (in a riding where he hand-picked the candidate, who also happens to be an ex-NDPer) or in BC (in Vancouver Quadra, John Turner's old riding) or both could be catastrophic for the bespectacled one's leadership.

I think that the Liberals will win three of the four races, losing in Saskatchewan but winning in Vancouver by a smaller-than-usual margin of victory. All told, tonight should be enough for people to dial back the outward criticism of Dion a bit.

And it won't likely be because of any stronger love or affection for the leader. Instead, the drumbeat for electoral war with the Conservatives will grow louder within the Grit caucus. And that could spell problems for Harper.

The Prime Minister has seen his party make uncharacteristic errors as of late. The NAFTA/Obama mess was a serious strategic error by a government renowned for running a leak-free ship. The Cadman affair still bubbles below the surface, threatening to explode at any moment.

But the most glaring miscalculation affecting the Tories' chances at a majority government is Harper's decision to hold the by-elections now. By assuming the government would no longer be standing, he figured these votes would never take place since a general election would have overridden the necessity for a mid-term vote. But the Liberals refused to oblige and, miracle of miracles, there's been no general election campaign.

If the Grits make a big splash and sweep today they can indeed gain some momentum as other commentators noted in their articles this morning. Combined with the other mistakes the Tories have recently made, Liberals might like their chances if they go now, before they get viewed irrevocably as the Harper government's political enablers. The risk to Harper is that people start to view the Liberal team, irrespective of their opinion of Dion, as the better group to govern. After all, the Harper team consists of Harper, Flaherty, Baird and a bunch of other people. Liberals may reason that they are as vulnerable as they ever will be right after a series of by-election losses today.

At any rate, any further delay in an election basically negates the need to bring them down early, thereby letting Harper become the first Canadian Prime Minister to serve his first four years in office at the head of a one-term minority government. By then, Canadians might be asking: "Why not give them the majority they want? They basically have it already thanks to the Liberals."

And there, ultimately, is the greatest risk to Dion -- parliamentary irrelevance. Coupled with internal dissent and an election loss a year from now, he'd be toast. Better to git 'er dunn when you've got at least a soft breeze in your sails.

I hope you're ready. This election campaign is coming sooner, rather than later.