If anyone in their right mind thinks Obama can win PA with only 75% of Dems, they are nuts. Morris says the indies are going 7:1 (!!) in favor of McCain. The numbers just don't work.
FOR OBAMA TO WIN THE ELECTION, LET ALONE PA, HE ABSOLUTELY MUST GET 90% OF THE DEM VOTE.
My own anecdotal evidence, based on various snippets of conversations, is that traditional blue-collar Dems are simply not going to vote for someone who is perceived as willing to tax them in order to send the proceeds to inner city blacks. (See, JtP for evidence of this motivation to "spread the wealth".)
Dems will rally if it's the 'little guy' vs evil corporations, or ways in which union wages can be raised, etc. In these cases, blacks were always used as a convenience to help them reach an electoral advantage, but that alliance is rendered moot when their interests collide.
If you haven't seen this Youtube video, I suggest you do so.