Pollster Jean-Marc Léger says there are three "magic moments" in an election campaign when the voters are up for grabs: the first 48 hours after the election is called, the 48 hours following the televised leaders' debates and the last 48 hours before the vote.
And the real objective of a leader in the debates is not to be declared the winner the morning after by either newspaper pundits or instant polls.
It's to put his or her party in a position to win more seats in the election a couple of weeks later. The harsh truth is that in elections, moral victories are for losers.
That's why, on my scorecard, the winners of this week's debates were Gilles Duceppe and Jack Layton, while Elizabeth May at least showed that she is not just a single-issue politician. And the losers were Stephen Harper and, especially, Stéphane Dion.
Many have credited Dion with being a winner of the first, French-language debate, especially since that's what the post-debate polls said.
But as to whether the debate gave Dion's Liberals even a temporary bounce in popularity, the polls were inconclusive.
The Quebec-based CROP firm reported a gain of only three points for the Liberals in this province since last week, to 17 per cent of all voters, including those expressing no party preference. And that was well within its six-point margin of error.
Dion exceeded Quebecers' low expectations in the French debate, but they weren't going to vote for his party anyway.
And in the English debate, his performance was nothing short of disastrous.
These were his first such debates, and he had been reminded constantly that his English was poor and that nothing less than his career was riding on this single performance. So he went into the debate inexperienced, lacking confidence and under crushing pressure.
And it showed, from the start. The solid grasp of the issues he had demonstrated in the French debate was not apparent. He had such difficulty expressing himself that it was left to May of the Green Party to explain the principles underlying Dion's Green Shift policy.
He looked and sounded nothing like a prime minister, but rather some small, terrified animal, eyes wide and voice high-pitched and occasionally trembling. Instead of confidence, he inspired pity. Had this been a boxing match, to which these debates are often likened, the referee surely would have stopped it.
For that matter, he didn't even resemble the leader of the opposition that he was in the former Parliament. It was Layton who assumed that role in the English debate, while trying to take support away from Dion.
Early in the debate, when the audience is largest and its interest highest, first May and then Layton exposed the weak spot that the Conservatives have tried to cover up with a sweater vest in their television spots: the perception that their leader is a cold-blooded "reptile," as he has been called by La Presse columnist Vincent Marissal.
They did so by accusing Harper of complacency and lacking understanding and empathy for ordinary Canadians worried by economic uncertainty.
And during the debates, Harper would sometimes smile disconcertingly at inopportune moments, such as while talking about people losing their jobs. It was as though he was suddenly remembering handlers' advice to show warmth, but the effect was creepy instead.
More often, however, Harper appeared to be sighing wearily as he endured a beating. In the election, facing a divided left as the leader of a united right is an advantage for Harper. But in the debates, it meant he had to face four adversaries alone, though Layton and Dion also squared off against each other. So Harper was mostly on the defensive, and with each leader entitled to equal time, he couldn't possibly respond to all the attacks against him.
Some of them were bound to stick, and in the French debate, the beneficiary was the Bloc Québécois, which was and still is in a two-way fight with the Conservatives in French Quebec. In the English debate, thanks to Layton's easily overshadowing Dion, it was probably the New Democratic Party that benefitted most.
Dion was big loser in debate
The Liberal leader looked nothing like a prime minister in the English debate