I think your parsing of DL reads in too much cynicism on his part. I think he genuinely sees Santorum as the true conservative, not Newt. I think he’s rigidly applying the formula that one should support the purest conservative in the primary and then suck it up and support whoever the nominee happens to be in the general. Unfortunately in our present circumstances this could very well help Romney get the nomination. But I don’t think this means he’s starting with a desire to see Romney get it. I just think that’s where his adherence to the formula takes him. I would say that he realizes this on some level, and I would guess that he himself isn’t totally comfortabe with the implications of what he’s written. I think he’s being formulaic and inflexible, maybe even a little bit naive, but not cynical. I don’t think DL is an establishment guy or a cynic, but I think he has managed to wedge himself into a position that can look that way from certain angles.
There's only one small problem with the 2012 bottling of this formula. If Romney is the nominee, then Limbaugh is urging conservatives to rally around a man who is the very antithesis of conservatism. It could very well mean the end of conservative participation in the GOP. I can't speak for others, but if Romney is the nominee, I will not only actively campaign AGAINST him, but burn my Republican Party registration card. Happily.
In short, the "formula" needs to be tossed. Its expiration date has passed. It's poison.