Think about the significance of last night. John McCain won South Carolina. The state that for decades has every Republican who has won it go on to the nomination. The state where "dirty politics" ended McCain's hopes of being President in 2000.
Political junkies need to step back and realize that most people, not even most caucus voters, care about this sort of thing that much.
But McCain managed a few things:
1. Effectively killed off every campaign but Romney's, while Giuliani's languishes separately.
2. Got more good news coverage.
3. Continued his momentum.
But let's not overstate the importance of things like this being the state that ended his 2000 campaign...most people just don't care.