The generic signs and banners at an election rally aren't usually worth a second glance. But at Stéphane Dion's campaign launch in Ottawa, among the dozens of standard-issue Liberal-red placards being waved by his supporters, a rather drab white one stood out. It bore no slogan, no candidate's name, just the words "National Women's Liberal Commission" in not very large print. The commission works to promote equal participation by women in the party. When the cheering was over, Maria Al-Masani, the 24-year-old campaign volunteer holding the sign, said she was glad to hear Dion announce that at least a third of Liberal candidates in this election are women. "It's a concrete measure," she said. "It's not just talk."

Al-Masani is the sort of female supporter Liberals like to point to when they tout their traditional edge among women voters. It's been a key strategic advantage in recent elections. In fact, analysts point out that if Conservatives had attracted as high a share of women voters as they did of men in the 2006 election, Stephen Harper would almost certainly have won a majority. So at the start of the 2008 race, Liberals have reason to be alarmed as polls suggest they've lost their crucial gender-gap lead among women, while the Tories' traditional advantage among men appears to be holding up.

Alarmed, that is, if they are paying much attention. In fact, the apparent disappearance of the Liberals' widely assumed lead among women is arguably the most overlooked big factor at the outset of this campaign, and not only in news reports and pundits' chatter. Some senior Liberal officials contacted by Maclean's said they hadn't yet focused on public polls showing their female-vote edge is in jeopardy. Yet the numbers are dramatic enough for Donna Dasko, senior vice-president of the polling firm Environics Research Group, to call the largely unheralded pre-campaign evaporation of the old pro-Liberal tendency among Canadian women "extraordinary" and "perplexing."

Those numbers are pretty clear. Environics' big pre-election poll for the CBC, surveying an unusually large sample of 2,505 potential voters in the week before the campaign began, discovered that many more women were planning to vote for the Tories than for the Liberals. Overall, the poll found 38 per cent of Canadians supporting the Conservatives, 28 per cent the Liberals, 19 per cent the NDP, eight the Bloc Québécois, and seven the Greens. The Tory lead, after months of the top two parties polling roughly neck-and-neck, got plenty of attention. Mostly overlooked, though, was the even more surprising gender split: the Conservatives led not only among men, with 41 per cent to the Liberals' 28 per cent, but were also strides ahead among women, boasting a 35 to 28 per cent lead. "I find this an extremely interesting development," Dasko said. "I can't quite figure out why it is. There certainly has been a traditional advantage for the Liberals in women's votes."

And her finding doesn't look like an aberration. Environics' previous national political preferences poll, conducted in late June and early July, also showed the Tories two percentage points ahead of the Liberals among women, 32 to 30. In March, the two leading parties were tied among women, 30 to 30. In other words, the three polls taken together show the Tories steadily tracking upward in women's support. Other polling firms are turning up similar findings — the Conservatives easily competitive with the Liberals among women, while maintaining front-runner status among men.

Liberal strategists did not sound particularly shaken when the numbers were pointed out to them. "It has to do with millions of dollars in pre-campaign Tory ads bringing down Mr. Dion," said one top party official, predicting women will return to the Liberal fold during the campaign. They'll have to for Dion to avoid disaster. Michael Marzolini, the Liberal party's long-time top pollster, leaves no doubt about what the gender voting split represents: the difference between victory and defeat. "If the Liberals don't have an advantage among women, they do not win," Marzolini told Maclean's. "Especially women over 55 — that is over 25 per cent of the entire electorate."

If the Tories are now looking surprisingly strong among women, they are hardly taking them for granted. Who was the target audience of those fireside-chat TV ads, released by the Conservatives just before the writ was dropped, in which Harper, casually clad in a sweater vest, leans forward to talk about his relationship with his son? Which voters did the Tories have in mind when they positioned the Prime Minister at the kitchen table of the Huang family in Richmond, B.C., right next to their 14-month-old son Eric in his high chair, for the first major campaign photo-op? Women, first and foremost, were in the Tories' crosshairs in the early going.