In many respects the most interesting moment in the second presidential candidates’ debate didn’t involve Libya or “binders full of women” or any of the other stuff post-debate chatter centered on. It was when an undecided voter fulfilled my own pre-debate fantasy by flatting asking Mitt Romney how he differentiated himself from George W. Bush.

In his latest Bloomberg column, Ezra Klein says that was a very important question for Romney to crush–but he didn’t. First, he wandered off into a neurotic or evasive effort to go back to an earlier question. And then he basically just recited most of his “five-point plan for jobs and growth” while asserting that’s what made him different from Bush.

It was a pretty bold effort to count on voter amnesia or ignorance about Bush’s policies, and just stay on message. As Ezra notes, there’s not much of anything in Mitt’s five-point plan that Bush couldn’t have (or didn’t) embrace as well, up to and including a balanced-budget pledge neither man seems to have had any intention of keeping.

But Obama’s follow-up to Mitt’s evasions was interesting as well. He could have done what Ezra did in his column in pointing out that the big economic policies that led to the 2008 disaster remain part of the Romney/Ryan agenda. But instead, he focused on the areas where Romney has parted company with Bush in a more radically conservative direction: immigration reform, most obviously, but also Medicare voucherization (half-true) and a ban on funding for Planned Parenthood (which W. would probably have supported if asked, despite Poppy’s identification with the group).

In taking this tack, Obama sacrificed the opportunity to identify Mitt with W. in order to attack the “Moderate Mitt Meme.” But it might have been a lot more effective had he pointed out that Mitt’s party has decided almost unanimously that Bush was a bad president because he was too moderate. This was the verdict after the 2008 defeat, and was the constant refrain of the 2012 Republican primary season: the GOP had erred not by pursuing endless high-end tax cuts or relentless deregulation of the financial sector or a dumb war with Iraq followed by a disastrous occupation, but by creating Medicare Part D and No Child Left behind and embracing comprehensive immigration reform. Bush was equally faulted for failing to undertake (with the exception of his abortive Social Security offensive in 2005) the kind of assault on the big New Deal and Great Society programs now associated with the Ryan Budget.

I realize that’s a mouthful for a debate, but probably would have involved no more words than were expended by Obama in defending his record on oil and gas permits. As it is, Obama did use Bush’s record to undermine Romney’s latest self-presentation, but did not clearly tie Romney to the worst Bush policies and to a party determined to make them far worse. As it happens, the Romney-equals-Bush litany is being hammered in pretty regularly on the campaign trail by Bill Clinton, but you do get the sense Romney’s getting away with more than he should on this very important front.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.