The attack on Jack has begun.
The Liberals are looking for something, anything, that can stop the NDP surge spreading out from Quebec.
To do so, the Liberals need to strip Mr. Layton of his veneer of happy pragmatism, and to brand the NDP as being wildly out of touch with the concerns of middle-class voters.
The inescapable problem the Liberals face is this: Large parts of the NDP and Liberal platforms are indistinguishable, something that the NDP leader pointed out Saturday - cheerfully, of course.
"When you look at the Liberals complaining about our platform … why did they copy most of it?" Mr. Layton joked.
All questions of authorship aside, there's no better example of the Liberal dilemma than the attempted assault on the NDP's climate change plan.
According to a Liberal statement released Saturday, Mr. Layton is a fiscal gambler, depending on "fantasy money" in the current fiscal year from a cap-and-trade system that would auction off $3.6-billion in greenhouse gas permits to big industrial emitters.
Ridiculous, say the Liberals. That kind of system might not exist until 2015. Mr. Layton will have to raise taxes, pile up more deficit spending, or simply break his promises.
That critique makes sense, in isolation. A cap-and-trade system is devilishly complicated to set up, and doing so in under a year does seem unlikely. Those funds are not likely to materialize, although the NDP has said it will delay some spending if revenue comes less quickly than forecast.
The problem for the Liberals is this: They envision having their own cap-and-trade system, functioning long before 2015, not much later than the NDP. Within a year, two years at the most, the Liberal program would be operating, according to Liberal environment critic Gerard Kennedy.
"We'd have a bit of a hurry-up agenda," Mr. Kennedy said in an interview in the opening week of the campaign, adding that a Liberal government would convene a first ministers' meeting that included climate change issues in this calendar year.
"We do believe that it's possible to do within a year or two, to have something up and running," he said.
(To be fair to Mr. Kennedy, he was speaking when Conservative inaction on climate change was the target, rather than the NDP's supposedly too-aggressive approach.)
The Liberals seek to split an exceedingly slender hair: The tax-loving, unrealistic NDP would move within 10 months to set up a carbon trading system and use whatever funds it generates to pay for green programs.
But the fiscally responsible, thrifty Liberals would take 12 to 24 months to set up a carbon trading system and use whatever funds it generates to pay for green programs. Two months, evidently, is the difference between a fiscal apocalypse, and responsible government.
Perhaps the Liberal war room can divine the difference; it's doubtful that Canadian voters can manage the feat.
Undoubtedly, the Conservatives are quietly cheering from the sidelines for the Liberals' big attack on Mr. Layton, and the message that this is no time for risky new schemes that could increase taxes. Stephen Harper couldn't have wished for a better ballot question.