Ben Carson has been beating the odds throughout his life. Raised by an illiterate single mother in Detroit, Carson rose to become a Yale student, a doctor, the youngest head of a division at John Hopkins, and a pioneer in neurosurgery. Things that should have been impossible seemed to simply melt away in the face of his intellect, ambition, and luck.

It’s easy to imagine that Carson expected the same to happen in his run for president. But after he briefly topped the polls in November 2015, Carson’s standing nosedived. Bedeviled by staff tumult and his own unpreparedness as a candidate, he was unable to win any nominating contest. The Washington Post reports that Carson does not see a “path forward” in the race. In a suitably weird end finish to what has been an odd candidacy, Carson won’t suspend his campaign on Wednesday after barely registering in Super Tuesday balloting. Instead, he will skip Thursday night’s Republican debate and give a speech as scheduled on Friday at the Conservative Political Action Conference in D.C.

The apparent end of the road for Carson caps his improbable journey. The retired neurosurgeon was once a popular figure in the black community, particularly in Baltimore. He was mentioned on The Wire, and my colleague Ta-Nehisi Coates has recalled how Carson was a role model to African Americans in Charm City. But Carson seems to have given little thought to electoral politics.

All of that changed in February 2013, when Carson spoke at the National Prayer Breakfast in Washington. It wasn’t his first appearance there—he'd done the same in 1997—but it was very different from the previous turn. Standing next to President Obama, Carson unleashed an unexpectedly political speech. He complained about political correctness, worried about the national debt, and blasted Obama’s health-care overhaul.

The speech was an instant hit. Conservative opinionmakers ecstatically lauded Carson as a fresh voice on the scene, and The Wall Street Journal wrote an editorial titled, “Ben Carson for President.” It didn’t hurt that at a time when conservatives felt they were accused of racism at every turn, they now saw a black man standing up and voicing the same ideas as themselves. And he seemed like a more promising prospect previous African American Republican hopes—more charisma than Alan Keyes, none of the personal baggage of Herman Cain. His views meshed well with the religious, socially conservative wing of the GOP too.

The idea of running for president had apparently never occurred to Carson before, but it captivated him. It also captivated others, including Armstrong Williams, a longtime black conservative macher and personal business manager to Carson, and John Philip Sousa IV, the great-grandson of the bandleader. Williams began grooming Carson for a run, while Sousa launched a draft Carson effort and political action committee. The doctor began preparing for a run, and declared his candidacy officially in May 2015.

But conservatives would come to discover that while Carson had conservative instincts, he was unpredictable, both in the rhetoric he employed and in the policies he advocated. He called Obamacare “the worst thing that has happened in this nation since slavery” and suggested progressivism was acting in the U.S. in much the way Nazism did in Germany. Later, he likened ISIS to the Founding Fathers and blamed the Holocaust on gun control. At other times, he advocated for national control of the school system, anathema to conservatives.

Between Carson’s erratic views, soothingly expressed in his sleepy, husky, tenor, and the fact that no non-politician had won a major party’s nomination since the war hero Dwight Eisenhower in 1952, led most commentators to discount Carson’s chances in the race. They overlooked three factors. The first was the strong desire for an outsider among Republican voters, which also lifted Donald Trump. The second was the appeal of Carson’s low-key demeanor, which seemed for a time like a pleasant antidote to Trump’s bluster. The third was Carson’s incredible ability to raise money for his campaign.

It was the money that was most impressive. Carson’s campaign raised more than any other Republican, though some of them enjoyed greater super PAC backing—pulling in almost $60 million. Carson managed to do that with very little high-level backing. Instead, he was lifted by a deluge of small-dollar grassroots contributions. That method quickly raised objections. Despite the huge hauls Carson was bringing in, his campaign was plowing much of it right back into fundraising, using it to pay for expensive direct-mail and telemarketing efforts. As a result, he was spending very little on building a sustainable campaign infrastructure or on advertising, even as the campaign paid huge fees to companies owned by or closely tied to his aides.

Critics worried that Carson’s campaign was effectively a grift, redistributing the hard-earned money of naive small-dollar donors to the pockets of big marketing companies. Others accused him of using the political campaign as a book-marketing tour, a charge he denied. Carson’s aides insisted that they were building up the base for a sustainable operation later down the line. As the campaign dragged on, Carson's burn rate remained high, even as his standing in the polls declined. That made it much harder to believe that everything was on the up-and-up. By late February, even Carson was implying that the campaign had perhaps been a scam perpetrated by ex-aides.

Carson’s political fortunes were harmed less by questions about fundraising than by his own shortcomings as a candidate. His political identity was premised mostly on a powerful personal narrative of overcoming barriers. Some of the parts of that story became subject to harsh scrutiny. Carson claimed he had been offered a full scholarship to West Point, but on closer inspection it became clear that he’d never actually been appointed to the academy, and that all cadets are on full scholarship. One important turning point in his life, he said, was when he tried to stab a friend, only to hit his belt buckle. Carson said that moment caused him to reassess his future, but reporters couldn’t find any evidence the incident had happened, and classmates described Carson as an affable, driven, well-adjusted young man.

Early on, Carson’s lack of interest or involvement with policy was clear, but his steady, soft-spoken demeanor seemed to appeal to many voters who didn’t seem to care that his answers to substantive questions were often meandering, vague, or superficial. That seemed to change after the November 2015 attacks in Paris, when a new sense of urgency about security gripped the Republican field. Carson seemed out of his league on terrorism questions, and he offered odd statements like claiming Chinese troops were involved in Syria.

In mid-November, The New York Times spoke with one foreign-policy adviser, a former intelligence officer implicated in Iran-Contra named Duane Clarridge, who said, “Nobody has been able to sit down with him and have him get one iota of intelligent information about the Middle East.” The campaign tried to disavow the comments and attacked the newspaper for speaking to Clarridge. The Times noted that they’d been directed to Clarridge by Armstrong Williams.

That moment turned out to crystallize the weaknesses of the Carson campaign. First, there was a general ignorance of policy and a reliance on unreliable advisers. Second, there was a clear split between the aides Carson had hired to run his campaign and Williams, who seemed to be running his own shadow campaign, often at odds with the official campaign. Those tensions came to a head around the end of 2015. Carson strongly hinted at a staff shakeup, then reversed himself, but several top aides left anyway, criticizing Williams sharply on the way out.

By then, however, Carson was already sinking in the polls, and the departure of the few experienced political hands on his staff meant it would be nearly impossible to reverse the trends. In Iowa, where he had once led, Carson came in fourth in the caucuses. He lashed out at Ted Cruz, accusing the Texas senator’s aides of spreading a rumor that Carson was dropping out to encourage his supporters to back Cruz instead. The charge turned out to be true—Cruz apologized—but by then Carson was hardly a factor anyway. He didn’t draw more than 10 percent in any of the following states.

What will Carson’s legacy be in the campaign? It’s hard to think of a single policy idea that Carson championed, and that another candidate could now adopt. Even on health care, he failed to make much impression. If Republicans hoped that Carson would win over minorities to the GOP, that doesn’t seem to have happened either. In the last few weeks of his campaign, Carson was talking about race issues, but as a way to consolidate conservative support, not to win over new voters. He seems to have squandered some of his good standing in African American communities. Carson is also mentioned repeatedly as a potential Cabinet member, but it’s worth recalling that he twice turned down appointments to the most logical post, surgeon general, from George W. Bush and Barack Obama.

Instead, Carson seems more likely to return to what he was doing before: giving motivational speeches and writing bestselling books. For many people, running for president is a transformative, life-changing experience. For Carson, it seems to have been an exciting way to spend the last two years, but otherwise only a brief distraction from the peaceful retirement he’d envisioned before that fateful speech at the National Prayer Breakfast.