Gingrich is really good at this. He has been ever since he drove Tip O’Neill crazy in the early 1980s. When he can control his laser-mouth, it can be a powerful tool. He’s been controlling it so far. He may not be able to do so for long, but…do not underestimate the value of senior citizen hormones.
Dave Weigel dissects Gingrich's line of attack:
Shaming a businessman about the people he's "bankrupted" and "laid off" sounds like the work of an Occupier, not a private-enterprise loving conservative. Yes, it's true that Bain was not a job creation machine. Romney's being disengenuous when he says it was. But there's a perfectly respectable conservative ethos that defends what Bain did, arguing that the only responsibility of a corporation is to make money.
Adam Sorensen notes that Gingrich is counter-attacking, not attacking:
Gingrich is leading in a bunch of states now. He doesn’t need to tear down his opponents to win and a scorched earth campaign, which he probably doesn’t have money for anyway, could backfire. (The political science on that isn’t exactly settled). So his ability to counter-punch effectively whenever his opponents take a swing is a great asset for a front-runner. And for all the talk of Newt’s penchant for self-destructive bombast, he’s proved incredibly quick on his feet in this campaign.