[dragonwriter]

In the US we have a couple hundred; structurally, though, only at most two are usually meaningfully competitive at any given time (both locally and nationally, though historically not always the same two in every area as nationally), and which two are nationally conpetitive is very stable (though one of the two has changed at two different times in US history, one of which involved a significant period of only one national competitive party with internal factions.)

[Throaway198712]

I understand. In Canada we have only had two parties create a federal government. But 5 separate parties have formed government provincially. 5 parties have federal presence. And if we didn't have first-past-the-post voting, we would easily have Greens, NDPs, and others in seats of federal power.