Too bad that's what we've done... If you look at America's history, political parties have been divided by a few issues and that's it. For the most part, the political parties until the 1900s followed Washington's wish of not being divided. Sadly, these modern political parties have decided that issues must be divided by party. This has lead to pretty much every issue we face today to be voted against by one party simply because the other party thinks they can't support it because it's somehow a partisan idea.
The media has also made this worse by not documenting things objectively. Citizens think one party is pure evil and the other one is magically full of saints. Unless you ask a libertarian about which party is better, you'll probably get a terribly slanted view. I don't understand this. Both parties have some rotten people, but why is it expected of the American public (it is expected) to vilify one party?
Issues about whether the government should be small and whether agrarian life is best have left to be about whether the government should tax its citizens into submission and whether it should be a police state. The much more rigid divide in beliefs is good for no one. I can't vote for anyone without them contradicting some of my beliefs because I don't follow the awkward divide in political ideals.