But here's the thing about that ad : It's timid. It quotes a Wall Street Journal editorial, but uses none of the most damaging details and footage from Romney's past, parts of Romney's past he himself has, remarkably, managed not to have to face directly from his rivals this election cycle.
It raises a fundamental question (to borrow a favorite Newt formulation) about Gingrich's campaign: Is he trying to win, and is he employing a strategy that would move him toward something more than settling scores?
Start with his current targets: On the trail, Gingrich is still hitting Ron Paul every bit as hard as he is Romney.
Paul is not now and will not be a serious threat to the nomination. Gingrich's attacks on his foreign-policy positions might feel good to him and sound good to a mainstream GOP audience, but they won't determine the nomination.
Then there's Romney. Yes, Gingrich is starting to swing back, after his strategy of unilateral disarmament backfired in Iowa, or, more accurately, was blown away by Romney's well-heeled supporters who sent his campaign into a tailspin.
Yes, Gingrich might, as he's promising to start to do, unload on Romney with the trove of information that's already out there, or new fronts, tagging Romney with inconsistent support for conservative positions.
But the race really isn't about bringing down Romney, at least not yet. It's about becoming the alternative to Romney, a spot that's up for grabs still.
That post won't end up mattering unless the candidate to occupy it becomes the overwhelming choice of the three-fourths of Republicans who still favor someone not named Mitt.
That brings the discussion to Rick Santorum, whose meteoric rise in Iowa has brought him huge crowds in New Hampshire, with South Carolina an even better demographic fit down the road. He's the beneficiary of the same sort of surge Gingrich felt just a few weeks ago.
Here's what Gingrich said of Santorum, to Fox News' Greta Van Susteren , last night: "We're both conservatives. We're old friends."
All true enough. Yet they happen to be friends who are after the same crop of Republican voters.
Maintaining such friendships in the midst of the campaign probably feels about as good as settling scores from previous races. But that doesn't amount to a strategy aimed at winning a nomination.