The really good Harper quotes fall into two categories; the ones on Health Care and the ones bashing Canada. The Liberals have started to use the first of these, but they badly need fit the later into some kind of narrative.
I would paint him as once having been an Alberta separatist. This could be accomplished by repeatly refering to Harper's Separation, Alberta-style: It is time to seek a new relationship with Canada and emphasizing the following quotes.
1) "Canada appears content to become a second-tier socialistic country, boasting ever more loudly about its economy and social services to mask its second-rate status"
2) "Any country with Canada’s insecure smugness and resentment can be dangerous."
3) "We [Alberta] are the only province in Canada keeping pace with the top tier countries in the world. Now we must show that we will not stand for a second-tier country run by a third-world leader with fourth-class values."
4) "It is to take the bricks and begin building another home -- a stronger and much more autonomous Alberta. It is time to look at Quebec and to learn. What Albertans should take from this example is to become "maitres chez nous."
5) "You've got to remember that west of Winnipeg the ridings the Liberals hold are dominated by people who are either recent Asian immigrants or recent migrants from eastern Canada: people who live in ghettoes and who are not integrated into western Canadian society."