CALGARY (CP) - U.S. presidential candidate John Kerry (news - web sites)'s campaign veered north into Canada on Tuesday as his sister appealed to expatriate Americans to register for their absentee ballots. With all expectations of a tight election fight this November, the Democrats are looking everywhere for votes, Diana Kerry said during a stop in Calgary. "We do know that there's going to be battlegrounds in lots of places and we're fighting on every front," said Kerry, who chairs a group called Americans Overseas for Kerry. While there are no official numbers, estimates suggest there are upwards of 400,000...