Monday night's Republican presidential debate in Tampa, Fla., introduced "a new Mitt" and "a new Newt," says E.J. Dionne at The Washington Post. Gone was the "lackluster" Romney from the past two debates. Also absent was the fiery Gingrich who propelled himself to a surprising South Carolina win and the top of the Florida polls. Instead, on Monday night, Romney launched a full-frontal "kitchen-sink attack" on Gingrich, says Politico's Alexander Burns, debuting a "newly aggressive" style meant to showcase Romney's fighting skills and Gingrich's flaws. Did it work?

Romney successfully "knifed" Gingrich: All the fireworks happened in the debate's first 25 minutes, when Romney went after Gingrich "hammer and tongs," says Rod Dreher at The American Conservative. Mitt's "solid hits" on Newt's Freddie Mac lobbying record and embarrassing exit from Congress in the late '90s were enough to take the momentum out of the obviously "stunned" Gingrich. Essentially, "Romney knifed him early on, and Gingrich never really recovered."
"Liveblogging Tampa GOP debate"

But Newt survived: "Romney was brutal and totally on message" for the first half hour, "but then Newt came back, and I don't think I've ever seen him quite as on his game," says Josh Marshall at Talking Points Memo. He wasn't bombastic or explosive, but he rolled with the punches and got in a jab or two of his own. Gingrich is also now "playing the frontrunner card," which must really drive Romney nuts. Nothing Romney did truly stopped Newt's "explosive momentum," which means Gingrich won.
"Quick reax"

And Romney's fighter pose was unconvincing: Sometimes the newly aggressive Romney's "jabs connected," says John Romano in the Tampa Bay Times. "There were times when Gingrich appeared flustered, and times when he fought back." This was a new Romney: "An aggressive Romney. An indignant Romney. A defiant Romney." But Mitt doesn't need another persona — he needs to be himself, whoever that is. "Personally, I'd prefer to finally see an authentic Romney."
"Romney tries out the face of a fighter"

In the end, Gingrich "deflated" on his own: Romney "was only mildly effective at challenging Newt," but that was enough, says Jonathan Bernstein at The Washington Post. Gingrich froze up at one point, and when his rivals actually called him on his typically preposterous claims, "he just deflated." Newt was neutered without "a hooting and hollering crowd" of partisan Republicans to play to. And that's a real problem: With his "reputation as a brilliant debater" exposed as a fraud, what does Newt have left to offer?
"At Monday's GOP debate, Newt Gingrich was deflated"