One small note of caution in reading the otherwise impressive results for Obama last night: As I mentioned, Obama improved his showing among white Catholics in Virginia (a 49-48 lead) relative to Missouri (a 46-50 deficit) the week before. (I use Missouri as a baseline because it was a tight race and didn't really favor Obama demographically.) But, if you look at Maryland, which was supposed to be the friendliest of the three, Obama actually did worse among white Catholics there than in Virginia or Missouri, trailing Hillary 48-41.
I think there are a few things going on here: First, the white Catholics in Maryland are probably more likely to be white ethnics--i.e., first-, second-, or third-generation Irish, Italian, Polish--than are Catholics in Missouri and certainly those in Virginia. (Perusing the Almanac of American Politics, it looks like St. Louis at least is much more Germanic than Baltimore.) So we're probably talking about a slightly different demographic here. Second, Hillary had the support of a leading white-ethnic politician in Maryland--Governor and former Baltimore mayor Tommy Carc..., I mean Martin O'Malley--something she didn't have in Missouri.
Having said that, if you could look only at white ethnics, I bet you'd find Obama closing that gap in recent weeks, too. My point in flagging Maryland is just to say that he's not quite there yet, whereas you might think he was based on the white Catholic numbers elsewhere.
And, of course, it's white ethnics who are going to be critical in Ohio and Pennsylvania.