You're absolutely right, Alex. It's one of the USA's strongest virtues.People used to do the flip-flop routine here too, in the same instinctive way...between the Liberal and Conservative parties. But then the Conservatives made themselves so unpopular in the 1980's that they fragmented and virtually destroyed their national power base. Since then, Jean Chretien's Liberals have won every national election by default, and it has not been a good thing. It's the antithesis of true democracy.
By the way, people here also instinctively tend to vote in the federal opposition parties as provincial governments...figuring they can balance the party forces by so doing. In practive, however, it doesn't work. Unfortunately.
- LH