When the two-party system controls everything, down to how you can get your name on a ballot and re-organising Congressional districts, there is NO chance of a third party succeeding at any point in the near future. With the ultra-politicisation of everything that I see in the United States the problem is more institutionalised than simply a two-party mindset. In essence, the system is run in such a way that two-party rule is enforced.

My two-party sense.