Maggie Gallagher

It's Christmas, and war is breaking out all over.

Thank Iowa. The state's unusually early Jan. 3 start date -- three days before the Feast of the Epiphany -- has sparked a sudden outbreak of pugilism among presidential candidates right and left.

Barack Obama appears to have recognized at long last that he has to choose: Is he running for president or vice president? Down by double digits everywhere but Iowa, he has a few brief weeks to persuade Democrats that Hillary is not the inevitable nominee.

Meanwhile, Rudy chose the Politico Web site as the venue for taking off the gloves on Mitt Romney. It's time to "take the mask off and take a look at what kind of governor was he," announced Giuliani, later adding: "He throws stones at people. And then on that issue he usually has a worse record than whoever he's throwing stones at."

Yet invited to similarly unmask Sen. John McCain, the formerly pugnacious Rudy genteely declined. "He's one of my friends, and he's one of my heroes," Giuliani said before whacking into Romney once more.

Thus Rudy announced that he understands this truth: The GOP primary for president is either a one-man or a two-man race. Giuliani is a clear national front-runner, barring an unlikely meltdown on the part of the battle-tested former mayor.

And of all the other candidates in the GOP race, only one man is now in a position to threaten his victory -- Mitt Romney.

Romney leads in Iowa and New Hampshire. The latest Rasmussen poll shows him pulling into a tie with Fred Thompson in South Carolina (eight points ahead of a plummeting Rudy). Romney is within spitting distance of Giuliani in Michigan, meaning that he is the only candidate who could topple Rudy's status as the front-runner in time to move into the early delegate-rich multistate sweepstakes.

To win the nomination, Rudy needs to keep multiple pro-life candidates in the running. He needs social conservatives to divide up between alternative candidates, so he can win while pulling only a fraction of their votes. Or, to put it in the converse, in order to stop a pro-choicer from becoming the GOP nominee, pro-lifers need one horse, not three or four, to ride. Mitt Romney appears to be the only credible candidate for that honor.

Maggie Gallagher

Maggie Gallagher is a nationally syndicated columnist, a leading voice in the new marriage movement and co-author of The Case for Marriage: Why Married People Are Happier, Healthier, and Better Off Financially.