On the evening of Friday, June 4, Liberal Party officials ran focus groups in Vancouver, Ottawa and Mississauga, Ont., to gauge reaction to some radical attack ads they were thinking of unleashing on Stephen Harper's surging Conservatives.
With Liberal support in freefall, the party knew it had to do something extreme to turn around the campaign. One proposed ad, awkwardly titled "multiscene manifesto," said Mr. Harper would have sent troops to Iraq, would weaken gun laws and wouldn't protect a woman's right to choose.
At the Mississauga focus group, Jack Bensimon watched from behind a one-way mirror as Liberal campaign co-chairman David Herle read the script to voters who had initially said they were likely to vote Conservative.
Mr. Bensimon, who oversaw campaign advertising as president of Toronto ad firm Bensimon Byrne D'Arcy, couldn't believe the reaction. Several members of the focus group said the ad made them want to rethink their decision.
"I have never, in all my marketing experience, witnessed as powerful an impact for a single ad in a focus group as I saw that night," Mr. Bensimon said.
He knew that Liberal attempts to frame the ballot question as one about "health care versus tax cuts" were going nowhere, while the Conservatives were doing a surprisingly good job of winning votes by reflecting the public's anger at the sponsorship scandal.
One early Conservative ad, for example, showed taxpayer dollars flowing into a garbage truck.
So the Liberals, who had not planned to introduce such negative ads, reframed the question. Instead of using their ads to talk about health care and tax cuts, they played on fears of Mr. Harper.
"This was an election in which people had to choose between anger and fear," Mr. Bensimon said. "Are you more angry at the Liberals or more worried about what the Conservatives might do?"
The ad, with graphic images of a gun pointing toward the viewer and a dissolving Canadian flag, hit the airwaves on June 9.
Within two days, the Liberals say, internal party polling reflected a decline in Conservative support. Subsequent polls reflected the trend.
But Conservative strategist Geoff Norquay disputed that the ad helped the Liberals.
"I would categorically reject that, because our polling showed that the gun-in-the-face ad was found to be truly offensive by a tremendous number of Canadians," Mr. Norquay said.
Privately, other Conservative officials suggest the bigger setback was Alberta Premier Ralph Klein's suggestion that radical changes were imminent to his province's health-care system.
Ron Johnson, who was in charge of NDP advertising as president of Vancouver-based Now Communications Group Inc., said the Liberal ad was just one of several factors that ended any chance of a Conservative majority.
He pointed out that the NDP, which spent more on advertising in this campaign than ever, also used its ads to hammer home the notion that the Conservatives had a hidden agenda.
Jonathan Rose, a professor of politics at Queen's University in Kingston, Ont., said campaign ads tend to have a subtle impact on the electorate. But he said the ads do influence the way the media cover elections and the way pundits talk about them.
The negative Liberal ad may have been successful because it forced the media to discuss the assertions made within, Mr. Rose said.
"In so far as ads are framing devices, it was probably an effective, albeit overly simplistic framing device," he said.