1. Mitt Romney is tougher than people gave him credit for. He did not stay robotically to his front-runner strategy. He knew he had to take Rick Perry down a notch or two and he did. The choice of the Social Security issue was exactly right. Romney didn’t want to go near Medicare – or anything that might require him to talk about health care and the successful Obama-like plan he championed in Massachusetts. Social security was a no-brainer. It’s always important to bear in mind that the Republican electorate is older than the country as a whole. A lot of older conservatives may say all sorts of negative things about the “welfare state,” but they love Social Security because it’s essential to them. (And, of course, they would insist that it’s not “welfare.”) Remember, too, that Florida is an early primary and has a relatively elderly electorate. But it wasn’t just that Romney picked the right issue. It’s that he showed he can adjust to new circumstances. He could have been limping this morning. Instead, he has new life.

2. My guess is that Perry will gradually try to wiggle away from the Social Security issue, but he has placed a big premium on being tough and consistent, so that will be difficult. He was more competent than his critics expected him to be, but he did not blow anybody away and seemed shaky at points. He could have emerged from last night with a big advantage if he had reassured doubters and made Romney look defensive or stiff or unwilling to engage in combat. But my sense is that those with doubts going in had doubts going out, and Romney didn’t play the part Perry’s folks hoped he would. Perry is still very serious – for someone with such extreme views, he seemed at least gubernatorial if not exactly presidential. But now he’s got a race on his hands.

3. Much as I hate to agree with the conventional wisdom, it is largely right about this debate and especially right about Michele Bachmann. She didn’t register very much at all and did not shake the “this-is-a-Perry-Romney-Race” narrative. She needs to find some way to go after Perry. For now, people on the right end of the Republican Party seem to have decided that Perry can win a general election while Bachmann cannot. She needs to change their minds.

4. I can’t quite figure out what Jon Huntsmann is doing. He was good and competent, but (except for his very right-wing economic plan) he seems to be running for the Pundit’s Favorite role rather than to win a nomination. Bruce Babbitt in 1988 was that Pundit’s Favorite and a lot of people who covered that campaign (including me) still respect and like him. But Babbitt didn’t win. I still think independent voters in New Hampshire could give Huntsman a chance, but to the extent that Romney identifies himself as the “reasonable” conservative who will protect the party from Rick Perry, Huntsman will suffer. Oddly, Perry has hurt both Bachmann and Huntsman. Oddly, both Bachmann and Huntsman, so different in almost every way, share an interest in altering the narrative of this campaign. But you wonder how they could possibly team up to do it.

POSTSCRIPT – Partly because he is my friend and colleague, but mostly because what he wrote was smart and prescient, I want to share Bill Galston’s “strategy memo” to Mitt Romney, published on the New Republic blog before last night’s debate.

More from PostOpinions on the GOP debate:

Milbank: Perry comes out fighting

Rubin: Perry fails to impress in GOP debate

Thiessen: Perry’s narrow win

Gerson: Romney 1, Perry 0

Marcus: Perry doubles down on Social Security

Cohen: Last night’s winners and losers

Bernstein: Does it matter who won?