The spike in ratings for Stephen Harper's leadership after Tuesday's English-language debate has melted away as quickly as it came, but the Conservative chief still has a hefty edge.
Nanos Research recorded a surge for Mr. Harper on its leadership index after that first televised debate, when he jumped to 122.8 from 94.4. But when the next survey was conducted Thursday, he had slipped back to 103.3.
Pollster Nik Nanos called that a "normalization" for Mr. Harper, which does not appear to have be driven by any specific event or by Quebec respondents after Wednesday's French-language debate. The one-day blip in leadership scores didn't seem to translate into a significant bump in support Mr. Harper's Conservatives.
"The English leaders' debate is no longer news [so]he's back down to normal again," he said.
The Nanos leadership index is a one-day snapshot of Canadians attitudes toward the party leaders, with 400 respondents asked which leader they view as the most trustworthy, the most competent, and which has the best vision for Canada. The score is a total of all three.
Mr. Harper still holds a wide lead over NDP Leader Jack Layton and Liberal Leader Michael Ignatieff - but it's the relative ratings of those two opposition leaders that may be the trend to watch, Mr. Nanos said.
Mr. Layton, with a score of 60.4, is now rated firmly ahead of Mr. Ignatieff, with an index rating of 42.5. Mr. Layton's score rose Thursday, and Mr. Ignatieff's fell.
The perceptions of those two leaders is likely to have an impact on the key dynamic in the late days of the election campaign: whether those who seek to vote against Mr. Harper coalesce behind the second-place Liberals, or will be split more with the NDP. In recent days, the proportion who say they intend to vote for the NDP in Nanos polls has trended higher.
Part of Mr. Layton's lead over Mr. Ignatieff is driven by higher scores in Quebec, where he was rated tops among leaders even before what was widely viewed as a strong performance in Wednesday night's French-language debate.
The trick for Mr. Layton and the NDP is to convert that goodwill into votes in the province, and their problem, Mr. Nanos said, is that a real breakthrough would probably require an edge over the leader whose party dominates in the province - Gilles Duceppe of the Bloc Québécois.
But Mr. Duceppe enjoyed an increase in his Canada-wide leadership score, to 19.0, likely driven by a perception that he won Wednesday's French-language debate.
"I think unless there's some major problem with the Bloc, it's going to be difficult for [the NDP]to convert that goodwill in any kind of significant way," Mr. Nanos said.