The Republican Party will exist in name, though it may stand for something different than it stands for now. Remember, the modern Republican party was originally founded almost completely on an anti-slavery platform. At the time, it was the "liberal" party.

The money attached to the "Republican Party" means it'll never go away. The way things are going, the Christian Right is driving out the rest of the 'conservatives' and the Dems are going to be dominant in '08, and 2012 is going to be a major turning point for America- either it irrevocably turns Right and becomes the "Christian Nation" the religious right demands, or religion gets kicked out of politics for a long time.