And so it ends—not with a bang, but a wimp-out. Chris Christie, who had become the most courted reluctant Republican since Dwight Eisenhower, permanently closed the door Tuesday afternoon on a 2012 White House run: “Now is not my time. I have a commitment to New Jersey that I just can’t abandon.” A self-described “regular guy from New Jersey,” Christie exudes more self-confidence than even Rick Perry out shooting coyotes. During his marathon press conference that went on so long that all three cable news networks cut to commercials, Christie channeled Popeye with his declaration, “I am who I am.” But for all his seeming candor and self-awareness (“You’ve got to know who you are in this life”), Christie may be deluding himself with his implicit belief that his time will come again during another presidential cycle. In truth, the combination of a weak Republican field and a vulnerable Democratic incumbent is a shimmering opportunity that may appear only once in Christie’s political lifetime.

Mitt Romney has everything going for him as the GOP front-runner: crisp debate performances, a disciplined campaign style, and a nine-digit personal fortune that can cover any fund-raising shortfall. But unable to get above 25 percent in the national polls, what Romney lacks—either because of his man-for-all-seasons ideological history or his cool demeanor—are actual Republicans enthusiastic about his candidacy. Meanwhile, Rick Perry is in free fall, with the three-term Texas governor running neck-and-neck with Herman Cain, a pizza executive with a thorough grounding in pepperoni. Even before the Washington Post revealed that the Perry family hunting camp came with a racial slur as its name, the Texas governor’s scorn for Social Security and the federal income tax meant that he was not the sort of Republican who would run well into the battleground states of the Midwest.

Of course, there was no guarantee that Christie would have fared well as a late-starting candidate. For all his love of Bruce Springsteen’s music, Christie may not have been born to run for the presidency. Nothing in his background as a federal prosecutor and no-nonsense governor gives Christie instant expertise about Pakistan, monetary policy, or natural gas pipelines. Christie’s bantering with the press corps might invite memories of John McCain’s relaxed style during the 2000 primaries, or it might have produced a TV moment yanked out of context and derisively repeated on YouTube. About all that can be said about the Christie presidential campaign that was not to be was that it would have been infinitely more interesting than chronicling Romney’s long march as the candidate of inevitability.

If ever there is a moment for the Republican long-shots, it is now. For all the obvious weaknesses of Herman Cain, Rick Santorum, Jon Huntsman, and even Newt Gingrich and (yikes!) Michele Bachmann, each of them was willing to take the fatal step and to stand before the TV cameras to declare, “I am a candidate for president.” That act of ego-driven courage separates them from the long grey line of major GOP refusniks like Haley Barbour, Mitch Daniels, John Thune, and now Christie. As Woody Allen put it—and this is the accurate version courtesy of the Yale Book of Quotations—“Showing up is 80 percent of life.”

Romney does not offer a dramatic story line, but he certainly has been having a run of good fortune, with Christie’s this-time-it’s-final decision serving as the cherry on the cake. Perry’s problems with the fading coat of whitewash covering a rock emblazoned with the prior name of the hunting camp can serve as a symbol for the way that the I-am-a-winner veneer is fading off his presidential candidacy. While Romney has been attacking the Texas governor as if it were the eve of the Iowa caucuses, it is Perry who mangled beyond coherence a debate question about Pakistan and all but accused Federal Reserve chairman Ben Bernanke of contemplating treason. The suddenly fast-forward political calendar (New Year’s Eve again in Des Moines?) means that a month has been sliced from the time needed to knock Romney out of the catbird seat.

Make no mistake: There is no greater act of hubris in political journalism than pronouncing a presidential race all but over three months before the Iowa caucuses. Romney may never get over his 25-percent threshold, Perry could rebound, some other active candidate could surge, or a surprise Republican could emerge from the sidelines and start sprinting towards the end zone. But on the day that Chris Christie bowed out, the New Jersey governor could rightly look at the uninspiring Republican cast and have claimed in Marlon Brando-fashion, “I coulda been a contender.”

Walter Shapiro is a special correspondent for The New Republic. Follow him on Twitter @waltershapiroPD.