The US electoral system (or at least the common one; one or two states have flirted with modernising it) makes more than two parties unviable. In general countries without proportional representation or similar are two party systems (or occasionally 2.5 party systems like the UK, for historical reasons), countries with PR are multiparty.

Yeah that would be a great start. Sorry state of affairs in Canada and the US is that even when politicians run on a platform of election reform, they change their tune because the system worked for them. The excuse I hear most often is some form of the electorate being too stupid to navigate such a complicated system.

The _fairest_ PR systems actually are very complicated, which is why they're rarely used in practice. Systems like PR-STV, though, are both a lot fairer than first past the post, and relatively understandable (in countries that use them, most people understand the basic mechanics, and _everyone_ understands them well enough to use them correctly, even if the subtleties are lost on most people).

My vote is held hostage by the Democratic party. I'm reluctant to expound upon that because that will invite a partisan pile-on and I've had enough of that here.