Unfortunately I think it's more the race thing than the Obama terrorist / extreme leftist Socialist thing. But there does seem to be an undercurrent of being unsure of what would this guy really do if he got in office (maybe for example tax the heck out of blue collar workers and give 'em to welfare moms, etc.) that has people worried about him, and I don't think he'll get as much support from traditional blue collar union workers as Democratic candidates in the past did.
I know, that I know, that I know....that the "dirty little secret" in the Dim party is that thousands of registered Dim's are absolute rascists. And WILL not vote for a black man or woman.
Yes, it's sad, but it's true.