Chris Christie and Carly Fiorina have dropped out of the race, but New Hampshire’s failure to winnow the Republican field to two or three candidates is disastrous for the Party’s efforts to stop Donald Trump. Photograph by Gretchen Ertl / REUTERS

Chris Christie was cocky to the end. On Sunday, during a campaign appearance at Shooters Pub, in Exeter, New Hampshire, he mocked reporters who predicted his demise as “junior political analysts” and bragged, “I actually do this for a living.” But on Wednesday afternoon, back home in New Jersey, he announced that he was suspending his campaign for the Presidency.

Christie’s exit was predictable. He staked his campaign on doing well in New Hampshire, and when he failed to meet the test he set for himself he dropped out of the race. A similar process has gradually culled the Republican field from seventeen candidates (nine current or former governors, five current or former senators, and three people who have never served in office) down to a still-large post-New Hampshire field of seven: Donald Trump, John Kasich, Ted Cruz, Jeb Bush, Marco Rubio, Ben Carson, and Jim Gilmore.

Five candidates dropped out before the voting ever started. Rick Perry, Scott Walker, Bobby Jindal, Lindsey Graham, and George Pataki all failed to meet tests of fund-raising or support in the polls and quit. The Iowa caucuses, on February 1st, winnowed the field some more. The social conservatives Mike Huckabee, who won the state in 2008, and Rick Santorum, who won Iowa in 2012, left the race after dismal showings there. Rand Paul also quit after he failed to win much support among libertarian-oriented Iowans, who gave his father almost twenty-two per cent of the vote in 2012. Carly Fiorina joined Christie in dropping out the day after New Hampshire.

New Hampshire usually acts as an accelerant to this winnowing process, instantly transforming large fields into two- or three-person races. But this time it didn’t, and New Hampshire’s failure to sweep away the also-rans dramatically increases the odds that the Republican nomination process will end with Trump as the G.O.P. nominee.

To understand why the winnowing process has stalled, you have to look at the remaining candidates and understand their incentives for staying in the race. Start with Trump, now the likeliest person to win the nomination. He has effectively unlimited funds. He has a lead in delegates. He has solid leads in national polls and in the next state with a Republican primary, South Carolina. He came in a close second in Iowa and won New Hampshire with thirty-five per cent of the vote, more than doubling his nearest competitor’s total. Rarely has a Republican candidate who has won a gold and a silver in the first two states gone on to lose the G.O.P. nomination. (Bob Dole in 1988 is a notable exception.) What Trump lacks is any support among the ranks of the Republican Party’s elected officials, a circumstance that seemed to matter more than most everything else in recent G.O.P. nomination fights but that he has turned into a badge of honor. He is likely to stay in the race for the long haul.

Kasich won second place in New Hampshire. Like Christie, he banked everything on the state, but unlike Christie’s bet his paid off. He won what had become a coveted No. 2 spot with just under sixteen per cent of the vote. Kasich’s leap into second is disastrous for the Republican Party’s effort to stop Trump. His campaign is underfunded. He has little organization beyond New Hampshire. He has run as a moderate, and is one of the candidates least likely to be able to broaden his appeal and attract evangelicals and more-conservative Republicans. And yet he has no incentive to leave the race before March 15th, when his home state of Ohio votes. His second-place finish in New Hampshire will likely allow him to survive a poor showing in South Carolina, which votes on February 20th and has a more conservative electorate than New Hampshire, and hope for a miracle in Ohio.

Cruz, who won Iowa and came in third in New Hampshire, has been underappreciated and under-rewarded in the media for what is the second-best performance so far. He can attract a sizable base of evangelicals and very conservative Republicans in South Carolina and likely continue his streak of meeting or exceeding expectations. He is well positioned for the so-called S.E.C. primary, on March 1st, when seven Southern and border states, with large percentages of evangelicals, vote. His fund-raising has been excellent, and he has wealthy donors willing to support an array of super PACs. His weakness is the opposite of Kasich’s and was apparent in the Iowa and New Hampshire results: he will have trouble expanding outside his very conservative base and winning over mainstream conservatives. But he is a good bet to end up as the last man standing against Trump in a long primary campaign.

The New Hampshire results had good news and bad news for Bush. Kasich eclipsed him, but Bush still finished above Rubio, whom he has tried to destroy with millions of dollars in negative TV ads. Bush still has a large war chest. His brother, George W., is surprisingly popular among Republicans in South Carolina, and, like Kasich, who will wait for Ohio, Bush has little reason to exit the race until Florida votes, also on March 15th.

Rubio’s story is similar. His fifth-place finish was bad enough to severely damage his campaign, but not so bad that it will force him out of the race before the next contests. He has money and the endorsements from important Party leaders. He won a close third place in Iowa by appealing to anti-Trump, anti-Cruz conservatives, who are also plentiful in South Carolina. Like Bush, he seems unlikely to give up the race until he makes a stand in his home state of Florida.

And so New Hampshire has reinforced, rather than solved, the same collective-action problem that has plagued the Republican establishment since last summer: it is in the Party’s interest to rally around one candidate to take on Trump, but it’s not in the interest of any of the anti-Trump candidates to leave the race yet. As long as Cruz, Kasich, Bush, and Rubio stay in, they will divide a sizable chunk of the vote that could be consolidated against Trump, and Trump will be able to collect delegates with his thirty- to forty-per-cent share. Starting on March 15th, when states begin awarding all delegates to the winner, rather than dividing them up proportionally, Trump can use this divide-and-conquer strategy to cruise to the nomination by winning states with just a third or more of the vote.

Many analysts, including me, were too quick to dismiss Trump earlier in the 2016 campaign. We might now be overestimating his strength. It’s possible that South Carolina will do the job that New Hampshire has historically performed and winnow the race to three main candidates. Maybe New Hampshire’s misfire just delayed the culling. But for now there is still no clear candidate to whom anti-Trump voters, who still represent a majority of the Republican electorate, can flock.