The politics-by-the-numbers game we play has been quirkily friendly to Mitt Romney. He was able to waltz into New Hampshire a week before its Republican presidential primary boasting of being a winner in the Iowa caucuses.

He could do so despite the fact that he beat former Sen. Rick Santorum, a mere asterisk in the standings a week earlier, by the infinitesimal margin of eight votes. In doing so, and after spending millions in an 11th-hour effort to make up for his near-absenteeism in Iowa, he actually won six fewer votes than he had garnered in his second-place finish there four years ago.

Until that late gambling surge, the former Massachusetts governor had pretty much kissed off Iowa as unwelcome terrain. He poured most of his time, energy and campaign treasure into neighboring New Hampshire, which also had rejected him in 2008. He built the Granite State as a political "firewall" against expected bad news from Iowa this time around.

Instead, Mr. Romney was able to stage a ludicrous victory lap at a rally featuring the Republican who had whipped him there four years earlier, the irascible but ideologically elastic John McCain. Arguably more popular in New Hampshire than Mr. Romney, Mr. McCain played the good soldier. He vouched for Mr. Romney as a true conservative of the kind Mr. McCain himself has often been accused of not being.

Mr. Romney, like Mr. McCain in his failed 2008 presidential bid, has been keeping his eye on achieving the nomination of his conservative party. He has been saying what is necessary to satisfy the Republican base, and like Mr. McCain he will worry later about assuaging independent and moderate voters.

Mr. McCain could not resist chiding the man he went to New Hampshire to help by calling him "Landslide Romney" in light of his eight-vote margin of salvation in Iowa. In ways, it was reminiscent of Mr. McCain's reluctance to bury the hatchet with George W. Bush at a similarly staged rally in Pittsburgh in 2000.

On that occasion, however, the blood was still dripping from the brutal assault Mr. Bush had administered on Mr. McCain with a series of personal smears in that year's South Carolina primary. Mr. McCain blamed the smears for his loss of the GOP nomination, and remained visibly sullen.

This time around, Mr. McCain could be more genuine in his endorsement. In a sense, it was political payback for Mr. Romney's energetic backing of Mr. McCain in the 2008 race, in which the aging Arizonan and Vietnam War hero was handily beaten by Barack Obama. At the rally in Manchester, he told New Hampshire voters to send Mr. Romney into the Jan. 21 South Carolina primary "with such momentum that he can't be stopped."

That, indeed, is what Mr. Romney wants. But, realistically, he must avoid any further evidence, in a state in which he has spent so heavily, that there remain serious reservations about his nomination — or about his electability, the strong suit in his pitch for support so far.

In a pair of weekend debates in New Hampshire, Mr. Romney can expect to bear the brunt of the seething anger of former House Speaker Newt Gingrich about the Romney super PAC-backed advertising in Iowa that fueled Mr. Gingrich's slide to a fourth-place finish, with only 13 percent of the vote. Mr. Gingrich has essentially moved on to the South Carolina primary but is to participate in the New Hampshire debates, in which he can get maximum exposure for what is now clearly an anti-Romney mission.

Two rivals still standing, Mr. Santorum and former Utah Gov. Jon Huntsman (who skipped Iowa and is putting all his chips into a New Hampshire showing), will also be in the debates. Mr. Santorum, an often aggressive and acerbic campaigner, would be wise to accentuate his own positives and leave attacks on Mr. Romney to the revengeful Mr. Gingrich.

The essential task for Mr. Santorum is to consolidate the true conservative vote, not join in plunging the party into deeper negativity and discord. Iowa gave him a narrow opening, and all he needs in New Hampshire is to demonstrate some steam of his own to capitalize on it, short of any huge upset of Mr. Romney in his New England backyard.

Jules Witcover's latest book is "Joe Biden: A Life of Trial and Redemption" (William Morrow). His email is juleswitcover@comcast.net.