Selling a Candidate
When canvasing for a candidate I don't think it is enough to know the candidate's positions. Really, knowing how they voted or will vote on particular issues is only part of the story. Indeed, it isn't even really a story at all. It's just basic facts, no different then High School history drills on dates of famous battles of the Civil War.
You need to make a candidate compelling and you don't do that by simply reciting a laundry list of policy decisions. You need to explain why that candidate actually felt that voting that way was the right thing to do. You need to tell the real story of the candidate, not just their position on issues. Using the history example again, what makes an historical event compelling is not the names, dates and places but the why behind it. What makes the Civil War such a compelling story is why so many Americans, both North and South, were willing to sacrifice their lives in that great struggle (the same can be said for pretty much any war).
What makes a candidate compelling is not how they have voted or how they will vote but why they would care enough to even take the time to get involved in the first place.
Learn the candidates story. Tell the candidates story. All else is gravy.