Steven Taylor explains in plain English why America’s party system has essentially stayed a true two-party system, even though other countries with similar electoral systems (notably Britain and Canada) have accreted semi-successful minor parties as well. The secret: open primaries.
The basic goal in the primary is to convince voters not party elites, that you ought to be the party’s nominee. If there is sufficient support for your candidacy, you will get on the ballot. What could be more democratic (as in rule by the people) than that?
Works for me…