By all accounts, Mitt Romney won what may be the last Republican presidential debate. Little good it will do him if in the process he suffers the loss of the general election.

Romney's performance on Wednesday in Arizona was both adequate and alienating. Spraying out a fusillade of negative research, he oppo-bombed a flummoxed Rick Santorum. Mitt even had the nerve to attack Rick for endorsing Arlen Specter, his pro-abortion-rights GOP Senate colleague from Pennsylvania, for re-election in 2004. Santorum lacked the minimal deftness to respond that Romney himself was in favor of abortion rights back then. The Massachusetts governor who has morphed into a reborn Michigander pressed on: The author of RomneyCare accused Santorum of being responsible for ObamaCare because Specter voted for it. Santorum was also relentlessly earmarked on stage; the latest incarnation of the non-Romney suddenly looked like the also-ran he has been for most of the campaign. He earned a D+ grade from Game Change author Mark Halperin

In the Arizona debate, Mitt may have stanched his bleeding in the primaries, but he opened his veins for November.

The debate may have been a game changer in Michigan, letting Romney slip by next Tuesday in a state he should have carried with ease. If so, he will be on his way to a reluctant nomination primarily because no one else can be the nominee. 

It will be a negative victory for a mediocre politician. Halperin accorded Romney a middling B- for his debate performance. He was artificial as usual, stiff even while sitting in a chair instead of mechanically gesturing from a podium. He was a snarky know-it-all talking down to his opponents and CNN's John King. At any moment, he looked as if he was about to turn to Santorum and say, "You're fired." It was as if the office of the presidency was a codicil in his trust fund.

Romney's campaign, with superior resources and organization, packed the room with a claque that applauded on cue. But on television, the candidate continued his long march toward an image as unlikable as it is inauthentic. As the longtime political strategist and LGBT leader David Mixner observed to me, Romney came across as "everyone's boss." A months-long series of verbal missteps into indifference and callousness toward ordinary Americans, combined with the pressure in the primaries to move hard right, have already scarred Romney's favorability ratings with independents and general election voters. Among women, for example, the new Quinnipiac survey shows him with a net unfavorable of -15 percent

Therein lies the potentially fatal weakness that goes beyond the well-coiffed candidate's starched persona. As he demonstrated in this debate, he's so desperate to pander his way to the nomination that he's making it increasingly worthless. 

Yes, at first he tried to duck King's question about contraception, complaining that George Stephanopoulos had raised the issue in an earlier debate. "Why in the world," Romney pushed back, was "he going there?" But after Santorum raised the stakes with a jeremiad about "teens who are sexually active," Romney obviously felt compelled to join in the anti-birth-control chorus. He saw Santorum and raised him, bashing his vote for an appropriations bill that included a provision known as Title X, which provides reproductive services for women. 

Mitt's message was clear: I may not want to talk about it. My rhetoric isn't all that hot. (You haven't heard me mention Satan lately.) But I'll go where I have to, and if you want an extreme social conservative, I'm your man.

This may do for the primary — it may be essential — but it's a disaster in the making for the fall campaign. Romney's cynical hope has to be that his shape-shifting will convince voters he doesn't really mean this stuff. He can pray that his character weakness is his saving grace — that his reputation for lying about his beliefs will pull him back from the edge of a gender gap that will otherwise pose an unbridgeable barrier to the White House. The longer the primaries drag on, and the more he has to profess his hostility to women's rights, the less likely it is that he can ever convince the majority who are women to take a chance on him. 

But let's not stop there — because Romney's panderathon didn't. He praised Arizona's ethnic-profiling immigration law as a "model" for the nation. By November, this appeal to the Tea Party will ferment into political hemlock. As Karl Rove correctly calculated, a Republican nominee can't prevail without claiming about 40 percent of the Hispanic vote. George W. Bush got just enough — 44 percent — in his close re-election battle with John Kerry. Afterwards, Bush joined with Ted Kennedy and John McCain in an effort to enact immigration reform. The congressional GOP and the grassroots rebelled; McCain, facing the same xenophobia that suffuses this year's primary electorate, recanted. Republicans sounded like throwbacks to the Know-Nothings who spewed venom and violence against Catholic immigrants in the 19th century. 

On his way to losing the presidency, McCain won just 31 percent of Hispanics. In an ABC News/Latino Decisions for Univision News poll, only 25 percent now favor Romney over Obama. In the Arizona debate, Romney surely eroded even that. 

His campaign may be counting on picking a Hispanic running mate to inch back up — most probably Florida Sen. Marco Rubio, or conceivably one of the recently minted Hispanic governors of New Mexico or Nevada. But post-Palin, a conscientious nominee has to be careful in his vice-presidential vetting, especially with choices who have been in high office for less than two years. Moreover, Rubio, who's Cuban-American, could have limited appeal to other Hispanics. And in any event, a surname almost certainly can't make up for an anti-immigrant position that feeds on prejudice and propagates anti-ethnic slurs. 

Color and ethnic identification don't trump issues. Republican Michael Steele, an African-American, captured barely 20 percent of the African-American vote in his Maryland Senate bid in 2006. Voters who shared his race were repelled by the GOP's hostility to civil rights and economic justice. No other African-American seeking major office has done as well with African-Americans as Steele — and that high water mark was pathetically low. So for Romney, relying on a Hispanic running mate to sell or compensate for his shameful capitulation on immigration may be all he's got, but it won't be enough. 

This is not the GOP that has won in the past — where a grace note has modulated the mobilization of the base. The allegedly war-mongering Ronald Reagan, in his 1980 debate with Jimmy Carter, pledged to reduce and not use nuclear weapons — and it turned out that he meant it, to the consternation of the neocons. The first George Bush called for "a kinder, gentler" conservatism; the second for "compassionate conservatism" — even if it turned out he didn't mean it. In contrast, Romney boasts of a "severely" conservative ideology; as he kowtows to the right wing on social issues and immigration, he signals that he would tear us apart. And if the economy continues to improve, he's painting himself into a narrow electoral corner. The party of "no" may be about to select a nominee with "no exit" into the mainstream. 

From Oklahoma to Ohio, which both vote on March 6, and then on to Wisconsin and across the Midwest, Romney is well behind Santorum in the polls. He will have to keep pandering — and above all, right now, he has to win Michigan.

In the Arizona debate, he may have stanched his bleeding in the primaries, but he opened his veins for November.