By saying snotty things about Obama to reporters. Because, supposedly, a Republican President would be more likely to go on supporting NAFTA. (Which for the record, I think would be a bad thing.)
I have no idea if it's true, though there's plenty of reason to believe that it might be, the asshole. And yes, of course, American voters totally base their decisions on the opinions of the Canadian PM. *eyeroll* But god, even the idea that the Canadian government would try to nudge for a Republican is kind of... yuck. Not surprising, in Harper's case, but yuck. Can we set him on fire yet, or do we have to wait until he's out of office?
If he leaves office. Election now please. *dirty look*