The recent shutdown that occurred should be more than enough to allow Americans to see that their extreme separations of ideas are harmful not only to themselves, but to the whole nation itself. Of course there must be two different parties with different ideas because otherwise that would be unfair and freedom of speech must be heard. But if those ideas are too separate and clash too much, then it becomes a possible problem to the economy of the country and the world itself.
The founding fathers knew that having to major political parties would not result well. The dangers of two political parties is that the country would be separated by ideologies and not be able to see other points of view other than the ones of the designated parties. In a Democratic country such as the U.S, we thrive of many opinions and if we only result to two we are limiting the majority of peoples ideals and it causes political separation.
No one is stopping the American people from bringing in a new party, just look at the independents, they are growing very fast. If the American People wanted a different party they would vote for a new one. But that is not what we want. We pretty much unanimously side with one party and those parties happen to be Republican and Democrat.