Sabato et al have broken down the rest of the GOP primary race by date, delegate, and demographics. A couple thoughts:
1. Colorado notwithstanding, I have trouble seeing the Pacific Northwest and Mountain West states as tossups. Romney is going to have strong support from Mormons all over the region, and I suspect that Ron Paul will also bite into Santorum’s base. So to speak.
2. It’s very hard to see Romney giving up, or accepting a VP slot. Theoretically Romney could try again in 2016, but it’s doubtful that he’ll ever face a field this weak again. As we know, there’s nothing more dangerous than a Mitt with nothing left to lose. Santorum might have a chance in 2016, might be willing to accept the VP slot, and thus is less likely to go for broke.
3. The failure of Santorum to get on the ballot in Virginia (and apparently Indiana) is a real problem, forcing him not only to sweep the Midwest but also to chip away at Romney’s strongholds. I just don’t see it happening.
4. Gingrich may well cut into Santorum in the South, either in terms of margin or by taking a state. Although it’s hard to tell at this point, neither Gingrich nor Paul seem susceptible to the pressures that drive sane humans from Presidential races.
And so while baiting Lemieux is entertaining, I have to concur with his basic assessment; Mitt Romney remains overwhelmingly likely to win the GOP nomination. For you compulsive types that just have to bet, I don’t think I’d take the 15% that’s now being offered for Santorum; 10-1 is a bit more to my liking. I should also note that I don’t think that this is good for Romney in terms of his general election viability. Unlike in 2008 when two essentially identical Democratic candidates fought it out, I suspect that wrangling with Santorum will push Romney farther to the right than he’d like to be.