Romney’s message remains the weakest part of his candidacy. And that means, despite his skill with attack ads and in debate, his campaign could still face substantial obstacles. “At bottom the Newt insurgency is fueled by the sense that Mr. Romney’s tepid policy agenda reflects no fixed beliefs,” the Wall Street Journal editorial page’s William McGurn wrote Tuesday. “In fact, it’s telling that Mr. Romney’s GOP rivals are defined as non-Romneys, each standing for something lacking in the front-runner.”

That “something lacking” problem has not been fixed.

What now? The Gingrich campaign will argue that the race is between one candidate who has won two primaries versus one candidate who has won one — hardly a lopsided contest, and hardly a result to declare one man the overall winner. And they believe the longer Romney has to devote much of his muscle to attacking Gingrich, the more Romney hurts himself. At some point, Team Gingrich believes, voters will grow sick of the negativity and say to Romney, “Enough — what about you?”

That could well be wishful thinking among Team Gingrich. Even though Gingrich is pledging to continue the race for as long as it takes to win, the fact is, the former speaker presented a mortal threat to Romney in one of the nation’s largest states, and Romney turned that threat into a huge victory.