WASHINGTON -- Legacy? What legacy?

There was general amazement when (the now-muzzled) Bill Clinton did his red-faced, attack-dog, race-baiting performance in South Carolina. Friends, Democrats and longtime media sycophants were variously perplexed, repulsed, enraged, mystified and shocked that this beloved ex-president would so jeopardize his legacy by stooping so low.

What they don't understand is that for Clinton, there is no legacy. What he was doing on the low road from Iowa to South Carolina was fighting for a legacy -- a legacy that he knows history has denied him and that he has but one chance to redeem.

Clinton is a narcissist but also smart and analytic enough to distinguish adulation from achievement. Among Democrats, he is popular for twice giving them the White House, something no Democrat has done since FDR. And the bouquets he receives abroad are simply signs of the respect routinely given ex-presidents, though Clinton earns an extra dollop of fawning, with the accompanying fringe benefits, because he is (a) charming and (b) not George W. Bush.

But Clinton knows this is all written on sand. It is the stuff of celebrity. What gnaws at him is the verdict of history. What clearly enraged him more than anything this primary season was Barack Obama's statement that "Ronald Reagan changed the trajectory of America in a way that ... Bill Clinton did not."

The Clintons tried to use this against Obama by charging him with harboring secret Republican sympathies. It was a stupid charge that elicited only scorn. And not just because Obama is no Reaganite, but because Obama's assessment is so obviously true: Reagan was consequential. Clinton was not.

Reagan changed history. At home, he radically altered both the shape and perception of government. Abroad, he changed the entire structure of the international system by bringing down the Soviet empire, giving birth to a unipolar world of unprecedented American dominance.

By comparison, Clinton was a historical parenthesis. He can console himself -- with considerable justification -- that he simply drew the short straw in the chronological lottery: His time just happened to be the 1990s which, through no fault of his own, was the most inconsequential decade of the 20th century. His was the interval between the collapse of the Soviet Union on Dec. 26, 1991, and the return of history with a vengeance on Sept. 11, 2001.

Clinton's decade, that holiday from history, was certainly a time of peace and prosperity -- but a soporific Golden Age that made no great demands on leadership. What, after all, was his greatest crisis? A farcical sexual dalliance.

Clinton no doubt wishes he'd been president on 9/11. It is nearly impossible for a president to rise to greatness in the absence of a great crisis, preferably war. Theodore Roosevelt is the only clear counterexample, and Bill is no Teddy.

What is the legacy of the Clinton presidency? Consolidator of the Reagan revolution. As Dwight Eisenhower made permanent FDR's New Deal and Tony Blair institutionalized Thatcherism, Clinton consolidated Reaganism. He did so most symbolically with his 1996 State of the Union declaration that "the era of big government is over." And more concretely, with a presidency that only tinkered with such structural Reaganite changes as tax cuts and deregulation, and whose major domestic achievement was the abolition of welfare, Reagan's ultimate social bete noire.

These are serious achievements, but of a second order. Obama did little more than echo that truism. But one can imagine how it made Clinton burn. He is, after all, a relatively young man who has decades to brood over his lost opportunity for greatness and yet is constitutionally barred from doing anything about it.

Except for the spousal loophole. Hence his desperation, especially after Hillary's Iowa debacle, to rescue his only chance for historical vindication -- a return to the White House as Hillary's co-president. A chance to serve three, perhaps even four terms, the longest in history, longer even than FDR. The opportunity to have dominated a full quarter-century of American history, relegating the George W. Bush years to a parenthesis within Clinton's legacy.

It was to save this one chance, his last chance, to be historically consequential, that Bill Clinton blithely jeopardized principle, friendships, racial harmony in his own party and his own popularity in South Carolina.

Why not? Clinton knows that popularity is cheap, easily lost, easily regained. (See Lewinsky scandal.) But historical legacies are forever.

He wants one, desperately. But to get it he must return to the White House. And for that he must elect his wife. At any cost.

Why was he out of control in South Carolina? He wasn't. He was clawing for a second chance.