If we want to do away with the two party default one thing is clear. STOP CALLING THEM THIRD PARTIES! People get very confused, and really they already know nothing about ballot access. Say, other political parties, because what that does is diffuse this idea that the R’s and D’s are de facto the only real parties. Saying Third Party implies only three can fit on the ballot.
Here in, NC, I gave up pushing for the Green Party because the only time the local party structure works on getting ballot access is during election season. In this state that is the worst time. The Democratic leaning people get very defensive and that thing about Nader comes right out. It’s such a useful myth for the D’s.