The same two political parties, Republicans and Democrats, have divided power in the United States for almost 160 years. Populists, Progressives, Socialists and Dixiecrats have occasionally elected a senator or governor. Independent candidates such as Ross Perot or Ralph Nader may sometimes tilt a presidential race. But on Nov. 6, 2012, as in every election since before the Civil War, Americans will face a two-way choice: the party of Andrew Jackson or the party of Abraham Lincoln. Not so in Canada. Canada is governed by a party reassembled less than 10 years ago. The opposition party is a little older: It dates back to the 1960s.