Republicans vs. Democrats

How is it that the U.S. is split perfectly in two by the two reigning political parties? How can it be that voters vote almost exactly 50% vs 50% each presidential vote? It seems preposterous to me that a country of 300 million people would somehow find themselves split directly in twain, opposing each other.

In following with the populus, the rest of our government is likewise split. The Senate, the House of Representatives, the Judiciary. Every branch is split nearly in half, except for the Executive, which can only be controlled by one party.

The only explanation I can speculate is that the tweaking of each party to suit voters' preferences, as well as the time-honored tradition of gerrymandering, over time, has gradually developed this impenetrable parity. I believe a balance this perfect can only serve to perpetuate the two parties currently in power, which is exactly what I do not want.

I would love to see a new party rise to power in America that is based on rationalism and social responsibility. However, I'm afraid that will not happen, because with two parties so perfectly opposed, a voter is always obliged to vote for the lesser of two evils, else deal with the anxiety of feeling the vote was wasted.

How does a third party become a viable alternative? I'm really asking, because I know very little about political theory, which is probably already evident to anyone who does know.

1) There must be a secession of powerful politicians from the two encumbant parties to draw voters to it. Of course they must be motivated to secede, and there must be an entity, or idea, responsible for uniting them.

2) There must an extremely strong grass-roots movement to mobilize unprecedented numbers of voters in favor of the new party. This seems practically impossible.

3) One of the two major parties must become so crippled by dissention among its voters, that it either redefines itself, or is overtaken by a third party.

I just don't understand how I, as a voter, can only have the choice of voting for the bible-thumping Republican party, with its fear mongering, and its disgusting corporate handouts, or the fumbling Democratic party, with its uninspired, syrupy, legislative ineptitude.

No matter who the candidate is, they all become the same person the further up the ladder they go. They're forced to by their obligations to the party. It's a fact of life. We need more idealistic rationalists in government. Seems like the only kind of people in Washington D.C. are extremists. How about some extreme rationalism?