Clinton may be a slight favorite as we head beyond Super Tuesday, but this is still a very close race that will be competitive for a long time, precisely because Clinton and Obama are splitting the Democratic electorate down the middle: he's winning young, she's winning old; he's winning upper income, she's winning lower income; he's winning Blacks, she's winning Hispanics; he's winning men, she's winning women.

There is no reason to assume the voting patterns we've seen on the Democratic side won't continue. And if you look at the calendar moving forward, Obama should have the upper hand over the next three weeks until we get to Texas and Ohio on March 4th.

If the back and forth continues, as it most likely will, and neither Clinton nor Obama are able to reach the magic number of delegates, then we're going to circle back for a really nasty fight over Michigan and Florida.

For the last week the Clinton campaign has been laying the groundwork to push the DNC to seat the delegates from Michigan and Florida, which would obviously be advantageous for her and potentially put her over the top.

But such a move would also rend the party in two, with Obama supporters taking the understandable position that Clinton was trying to steal the nomination by changing the rules of the game midstream.

The longer this contest goes on, with the candidates like two heavyweight fighters trading blows in the middle of the ring but unable to land a knockout punch, the more likely the prospect of a intensely divisive conflict over the Florida and Michigan delegates becomes. Howard Dean must be dreading the thought.