I dont see how canvassing for a political agenda is tolerance of opposition. Sure, you'll run into people who disagree with you, but you don't tolerate their POV and are actively encouraging political action against their POV.
Actually, a lot more listening happens on a successful doorknock than most people would think. Listening and really hearing people is necessary, much more necessary than making a specific political point.
Also yeah, while I was actively campaigning I met many people from other parties - and the other side of the aisle, and stood next to them outside voting booths and had some nice conversations.
Encouraging people to rethink their political position isn't intolerant unless it cross over to some sort of coercion. There has to be an ability to argue what a best policy is, or there would be no reason for democracy in the first place.
