The biggest question is what percentage of the Clinton base will jump ship or simply not vote in November. Exit polls have indicated that number to be anywhere between 20% and over 40% depending on the state. The number tends higher in states like Kentucky and West Viriginia and lower in states like Oregon and Colorado. In the middle are states like North Carolina and Tennessee.
I do believe that Obama will recapture some of the Clinton base but even if he recaptures half of that approximate 6 million disaffected Democratic voters, that’s still 3 million voters he is not going to get. Can Obama win without those 3 million voters? I honestly don’t know yet. It is too early to tell.