Fight the premise!
Everytime you see or hear some talking head say "it's a two party system", just remember THAT IT IS NOT!
You cant really say "they're lying", because it's just become a colloquialism. Or whatever the proper term is for a phrase that has become so ingrained that people let it be said even though it's not a statement of fact.
Heck, there is even offically elected Independants and there will be more. Slowly, over time, with people all the while thinking short term saying "dont throw your vote away", those people are dumb. Ignore them.