Pawlenty, however, has no major liabilities. Oh, he used to accept scientific facts on climate change and a market-based plan to deal with it, and that’s an unacceptable position these days…but virtually every Republican politician has similar troubles on that issue, and Pawlenty has dealt with it pretty well. More to the point, Pawlenty was according to all reports a finalist for vice president in 2008, and I don’t recall any important GOP or movement conservative groups objecting. So why isn’t Pawlenty pulling away?

Perhaps he is, and we just don’t realize it yet. That’s the Dukakis analogy. Looking at Nate Silver’s data, Mike Dukakis was an apparent longshot based on early polling, sitting at about 8%. At this point in the 1988 process, Democrats were generally unenthusiastic about the field, distracted by implausible nominees (most notably, Jesse Jackson), and looking for a late entry to save them. Dukakis just rolled along, doing the things that candidates need to be doing, and by the time the actual voting came along he basically had the thing locked up, even though it took a while to get it done.