Ultimately, I think this contrast is likely to play into the hands of Perry in the Republican primaries, because right now the base wants somebody who is willing to shake things up and challenge the status quo. And there’s good reason for them to feel this way. For anything to get done about the nation’s long-term fiscal problems, we’ll need a president who is willing to embrace real changes to our existing entitlement structure. After watching this exchange, Perry seemed willing to do that, whereas Romney seemed to be offering more of the same. His general answer on Social Security tried to have it both ways. By defending the program as a great success that simply needed to be adjusted, it wasn’t all that different from Obama.

So I think Perry, with the Social Security answer, his strong defense of his death penalty record, touting of Texas’s economic performance, and his willingness to attack his rivals in a way that Tim Pawlenty was not, showed us why he shot up into the lead in national polls shortly after entering the race. Yet he seemed to tire as the debate wore on, and many of his answers — such as on global warming, foreign policy, the uninsured rate in Texas, and education — were evasive, vague and unfocused. While he didn’t make any major gaffes tonight, in future GOP debates, and especially if he becomes the nominee, he’ll have to come off as a long more polished and demonstrate a better grasp of specifics.

As for Romney, he came across as more polished than Perry, but also, as demonstrated by his Social Security answer, reinforced the view of himself as an establishment pick who wants to play it safe and who probably won’t be a dependable fighter for smaller government if elected.