For all the reverence the 'founding fathers' get they could have done a much better job setting things up. America got rid of royalty, then brought it back in by electing them, and not in a ceremonial function either. It's a huge problem (that, and the 'two party system').
Technically the two party system could change but things are set up in such a way that no third party will ever gather enough votes even if you were to say pit two un-electables against each other.