What Canadian would know what party you belong to, what address you live at, have your signature that matches your registration file, or have an electric bill with your name and address, and even know whether you voted or not, before he showed up to steal your vote, taking a chance of being caught red handed, especially when the volunteer checking the Canadian in, is the US Cit voter's sister in law and knows you?
NO THIEF would take that chance of getting caught in person.... unless he was retarded.