We're now mostly through the quadrennial discussion of why Iowa, New Hampshire and the other early voting states are not representative of the nation as a whole -- too small, too white, etc. The other thing that's become clear this year is that they are unrepresentatively open, with people outside the two major parties able to participate.

That's what, for me, was striking about John McCain's victory in South Carolina. Those of us in the political media are still in love with the notion of momentum and the question of whether McCain's win there will propel him to victory in Florida and then the multitude of primaries on Feb. 5 and so on to the nomination.

But McCain didn't carry Republicans in the South Carolina Republican primary. As in New Hampshire, his win rested on the backs of the independent voter. That may be all well and good for the general election, but as the primary season drags on more of the contests will only be open to the party faithful. That means McCain could still be vulnerable and the GOP still may be shopping for a frontrunner.

The polling in Florida, after all, looks like nothing so much as a four-car pileup.