Okay, the Yale stuff seems more interesting, and doesn't put so much faith in just its model.
Still, it's very hard to get good data and reconcile Obama's giant victory with such massive defections from a candidate that essentially tied him in primary voting.
Not really. The GOP was at rock bottom in 2008, coming off back to back wave elections ushering George W. Bush out of office. Dems picked up plenty of House seats and Senate seats in districts and states that Obama did not win.
The House Dems outperformed Obama in the 2008 election. Couple that with the primary electorate being a very small portion of general election electorate, and it becomes a lot more palatable.