1)pgil is right

2) easier to move than get a real third party going. You can't just change your vote. Change it to who?

3)if you look at the founding ideas of all major (and minor) parties, they all sound great. It's like saying the blurb on the back of a movie makes it look really good.

4) people live in american because they were born here. An amazing amount of them really don't want people to make their own decisions as it relates to religion, expression, drug use, gambling, abortion, gun control, etc. They have a view and they want people to abide by it.