I'd like to move in the direction of eliminating them, yes. I don't see any reason to keep US/Canadian border controls, given that the relative parity of incomes means there isn't likely to be some huge, destabilizing migration. The EU's Schengen free-travel zone is a good precedent to follow on that, imo. Mexico is a harder case because of how screwed up the country currently is; opening borders tends to work better between relatively stable countries. But certainly we could start with Canada.