A fifth-place finish in New Hampshire is not usually the slingshot into a two-way race for the Republican nomination, but Newt Gingrich can reasonably make the case.

The former House speaker stands second to Mitt Romney among Republicans in national polling. He ties for second in South Carolina. He is a clear second in Florida. With Rick Perry finishing just 800 votes ahead of Buddy Roemer in New Hampshire, Gingrich can claim to be the last viable Southerner in the race. He commands money for ads. And he has secured the all-important Todd Palin endorsement.

But the price Gingrich has paid for his continued relevance is high. He had hoped to succeed by confounding expectations about his volatility, hypocrisy and instability. Now he maintains public attention only by confirming those expectations.

While up in the polls, the relaunch of the Gingrich persona was the main theme of the Gingrich campaign. He would be “respectful and constructive.” He would disavow PAC attacks and fire staffers who engaged in negativity. In typical Gingrich fashion, it was not enough to claim virtue. He criticized other candidates for “acting like seventh-graders.”

Yet Gingrich, it turns out, is forever 14. When his record came under attack, he called Romney a “liar.” He complained of being “Romney-boated.” He dismissed his few weeks of holiday positivity as an “experiment,” promising that unflattering material on Romney would come daily. “Everything we say,” he announced, “will have Romney’s quote, Romney’s videotape, Romney’s record; it’ll all be based explicitly on Romney.” And then the Bain offensive.

In early December, Gingrich believed he owned the nomination. Now he thinks it was taken from him by Romney’s cheating. Actually, it is properly called vetting. Gingrich’s emotions are understandable. But it is the contrast between the winning Gingrich and the losing Gingrich that astounds. It requires the study not of politics but of lycanthropy: The moon rises. The transformation is complete.

The presidential nomination process is arguably too long and too undignified. But it is also revealing. It eventually leaves candidates stripped and naked. They cannot hide who they are. In Gingrich’s case, this campaign has summarized an entire career. He is a man of exceptional ability — fluent, persistent and creative. No one has a better feel for the pulse of conservatism, though he is occasionally willing — on an issue such as immigration — to buck conservative orthodoxy.

Yet Gingrich also pioneered the politics of personal destruction, as well as the politics of personal pique. Once again, he feels that his proper seat on Air Force One has been denied. So he attacks Romney from the right on abortion and from the left on Bain Capital. The only unifying principle — the only cause that is clearly served — is the emotional impulses of the man himself. He fights not for any brand of conservatism but for Newtism, which is more important to him than any party or ideology.

Gingrich recalls another impressive, flawed political figure. I have in mind a Southerner, attracted to big ideas, fascinated by management theories and scientific paradigms, prone to grandiosity and moralism, capable of both insight and bullying, leading through the cultivation of constant alarm. Al Gore was also transformed by defeat, which coincided with an “assault on reason,” a failure of “rational analysis” and the “shocking decay and degradation of our democracy.” The political failure of a figure so large required cosmic explanation. Gore’s opponents became “digital brown shirts” and “un-American” and a “renegade band of right-wing extremists” who had “betrayed the country.” Grievance merged with self-importance. It is easy to imagine Gore delivering Gingrich’s words: “If you want to smear people who are trying to think, fine.”

Newt Gingrich is becoming the Al Gore of the Republican Party — but with one large difference. By accepting the role of vindictive prophet, Gore appeals to a subset of the progressive coalition — the sort of people who find Keith Olbermann fair and balanced. (Gore, in fact, employs him.) Whatever Gore’s flaws, he is the leader of a cause.

It is currently difficult to discern any cause in the Gingrich campaign apart from Gingrich himself. He is the party of one — one world-historic leader, supported primarily by one billionaire. This is not a movement; it is the prosecution of a feud. Like Samson, Gingrich is willing to pull down the temple around him. But, in this case, it is not the Philistines who suffer. It is Republicans in the rubble.