Karl Rove has another piece in the Journal today:
The primary has created a deep fissure in Democratic ranks: blue collar, less affluent, less educated voters versus the white wine crowd of academics and upscale professionals (along with blacks and young people). Mr. Obama runs behind Mrs. Clinton's numbers when matched against Mr. McCain in key industrial battleground states. Less than half of Mrs. Clinton's backers in Indiana and North Carolina say they would support Mr. Obama if he were the nominee. In the most recent Fox News poll, two-and-a-half times as many Democrats break for Mr. McCain (15%) as Republicans defect to Mrs. Clinton (6%) and nearly twice as many Democrats support Mr. McCain (22%) as Republicans back Mr. Obama (13%). These "McCainocrat" defections could hurt badly.
Lots of bad news in there for McCain as well. Rove is still predicting a big bounce for Obama when he finally seals the deal, and obviously a lot of these Democrats will come home over the course of the general election, but there are likely to be more than a few bumps in the road between now and then. McCain is getting a lot of grief for his performance in recent primaries--losing more than 20 percent of Republican primary voters to a combination of Ron Paul, Mike Huckabee, and, in Indiana, Mitt Romney. But now that Obama is, in the eyes of the media at least, the presumptive nominee, it will be extremely embarrassing if he loses states (West Virginia, Kentucky, and possibly Puerto Rico) by margins of 20 percent or more to an already defeated Hillary Clinton. Imagine what the media would say about McCain if he lost a primary state at this point.