Two of the smartest guys I know --Victor Davis Hanson and Peter Robinson-- had a debate about whether Senator Clinton or Senator Obama would prevail.  Peter describes it here.

Ed Rendell's easy dealing of the race card noted below underscores Hanson's assertion about the Clinton's playing to win.

The Democrats are and remain a party of bosses --union bosses, interest group bosses like the folks running NOW and Emily's List, and even the netroots' bosses like Kos.  An Obama nomination would be a shattering event for all of these established and powerful hierarchies.  It isn't impossible given the extraordinary grassroots momentum he is generating, but because an Obama victory would be so unprecedented it is hard to imagine its consequences. 

Turning Obama back after his long stretch of wins would engender a great deal of bitterness as Peter notes, a disappointment not likely to be appreciably reduced y the almost inevitable offer of the vice presidency.

But an Obama nomination would be so destabilizing for Beltway bigs and their networked supporters that the effects could be deeply destructive for leadership elites through the various power centers.  When the revolution gets going, doesn't the Obama precedent spread through, say, the AFL-CIO and the NAACP and The Human Rights Campaign with demands by new voices that they be heard and that change come to their organizations as well?

The GOP is unsettled right now, but the smash-up underway within the Democrats could easily become the biggest since their 1968-1972 convulsions.