Just curious - both parties?

This goes both ways, so don't say that I'm trash-talking either party. I've noticed that when someone stated they were voting for Obama, McCain supporters (not fair to say ALL of the supporters, but a bunch!) have called them uneducated, stupid, young, and every imaginable insult. Also, it was the other way around, Obama supporters did do the same thing to McCain supporters. Why do we feel it is alright to degrade people this way? Aren't we all for the same thing -- to be the UNITED States? Why does everyone have to fight and hate each other? Might be a stupid question, but I was just curious what people would say .. ?