Every failed presidential campaign is a how-the-mighty-have-fallen story: a politician once strong or deluded enough to think he could lead the nation, humbled by the reality of the electorate’s indifference.

But Scott Walker’s fall was especially precipitous. The Wisconsin governor’s campaign lasted just 70 days. He came in as the Iowa frontrunner and departed a few weeks later as an asterisk, with too little support even to be assigned a number in the last national poll.

How does that happen? How does a politician make such a strong impression out of the gate, then disenchant virtually every person who once told a pollster he should be the next president? Walker didn’t make one giant, disqualifying gaffe. Instead, he made a series of small mistakes—tactical, strategic, rhetorical, and ideological—that added up to an unavoidable conclusion: No matter what, he would not be the nominee.

Walker started out strong—perhaps too strong. Speaking to a conservative confab in Iowa back in January, his lively but common-sense appeal made a major impression among conservatives in the early-voting state, and he rocketed into first place in a field that was just starting to take shape. (Though there wasn’t much doubt that he was running, Walker, citing his gubernatorial duties, wouldn’t officially declare his campaign until July.)

On paper, he seemed like an ideal candidate: He’d won three tough elections in a state generally dominated by Democrats, including a recall in 2012. His battles with public-sector unions had impressed national conservatives like the Koch brothers. He was a conservative who’d governed while taking on the status quo—a potent mix for a party whose restive base was tired of compromising and losing. As he liked to say, there were other candidates who were fighters and other candidates who were winners—but only Scott Walker was both.

But Walker’s unexpected early success was whatever you call the opposite of a blessing in disguise—a curse in disguise, perhaps. It made him overconfident, removing the incentive to put his head down, study policy, and work for votes, while training a harsh spotlight on his every utterance. Those utterances frequently made audiences and the media do double takes, as when he refused to say whether he considered President Obama a Christian, or when he claimed to be ready to take on the Islamic State because he’d taken on the unions. As the Washington Examiner’s Byron York wrote on Monday: “There had always been talk that Walker, as a Midwestern governor, wasn't well versed, or even very versed at all, in foreign policy. That turned out to be true.”

As a strategic matter, Walker may have chosen the wrong lane, or segment of the electorate. Correctly sensing conservatives’ desire for anti-establishment candidates, he tacked hard to the right, renouncing his previously moderate positions on immigration and emphasizing his social conservatism. In his blue state, Walker was used to being the most conservative guy in the room. But on the national stage, in a party tilting ever rightward, there was always someone willing to go farther, and many conservatives suspected him of posturing. When Donald Trump’s candidacy began to take off, Walker’s support in Iowa quickly evaporated. In the words of the Republican consultant Liz Mair, who had worked for Walker’s Wisconsin campaigns but was fired from his presidential effort for a handful of impolitic tweets, Walker failed because he became “so invested in winning, no matter what it took, that he lost sight of his real identity as a political leader.”

The practical effect of Walker’s hubris was a campaign that spent too much money too fast, on the assumption that its early flood of support would continue unabated. When the wheels began to come off and donors got skittish, there were too many mouths to feed. The super PAC supporting Walker was still flush with cash—two weeks ago, it reserved $7 million worth of television airtime in Iowa—but the actual campaign was broke. “People don’t stop running for president because they run out of ideas or run out of desire to keep giving speeches,” Terry Sullivan, campaign manager for Marco Rubio, said on Monday. “They stop because they run out of money.”

Last week’s Republican debate was the final straw. Walker had played it safe in the first debate last month, trying to seem serious and above the fray, only to find that he’d come across as boring and irrelevant. In the second, he vowed to strike a newly aggressive pose. He jumped in at the top with what was supposed to be a cutting insult of Trump: “We don’t need an apprentice in the White House,” he said. “We have one right now.” The line came across as corny, canned, and inaccurate: The whole point of The Apprentice, Trump's entrepreneurship-based reality show, was that Trump was not the apprentice but the master, with the contestants vying to be his apprentice. In any case, Walker didn’t manage to assert himself much for the rest of the debate, and was widely judged to be one of the night’s big losers.

Walker returns home badly damaged by his ill-starred foray onto the national stage. In Wisconsin, he’d built a fearsome reputation as a pol who couldn’t be toppled. He was known for his relentless discipline and ability to outsmart and outlast his rivals. But as a national candidate, he took stands that contrasted sharply with the rhetoric he’d used to get elected; he insulted his former colleagues in the Wisconsin legislature; and he seemed incapable of staying on message, especially on the immigration issue. Wisconsin’s once-dominant chief executive looks decidedly fallible, and even his allies doubt that he will run for a third term in 2018.

In his speech quitting the race on Monday, Walker depicted the Republican primary as a collective-action problem, with the sheer number of candidates preventing the electorate from coalescing around a responsible (read: non-Trump) choice. He urged other candidates to follow his lead and remove themselves from contention. But Walker, who is just 47, may have another strategic consideration in mind: safeguarding what’s left of his dignity with an eye to the future. Ever an astute political strategist, Walker has been here before. In 2005, he briefly entered the race for the 2006 gubernatorial nomination, only to drop out a few months later when it became apparent he couldn’t win. The move preserved his political reputation for 2010, when he ran and won. As Walker was dropping out on Monday, an operative in Milwaukee suggested a similar turn of events. “Past is prologue with Mr. Walker,” the operative texted. “National stage hasn’t seen the last of him.”