In downtown South Bend, Indiana, there’s an ugly concrete building where people can pay their water bill in person. When Pete Buttigieg first became mayor, in 2012, at age 29, this fact drove him insane. “How the hell is it that we’re still collecting cash payments in person for utilities in a modern city in the U.S.?” he asked me, faithfully reproducing his earlier exasperation.

South Bend was struggling economically, which meant the city needed to get more efficient and fast. Closing the payments office would be a step in that direction. Buttigieg once told a reporter that his "primary interest is using technology to improve people’s lives.” The payments office seemed to be doing neither.

But Buttigieg changed his mind about shutting the place down. “It turns out there are enough people who are completely unbanked,” he told me, “or so socially isolated that this is one of their few outings, that there’s an uncapturable virtue to having this there even though it doesn’t pencil out.”

Buttiegieg applied his technocratic know-how to South Bend's public services. Lyndon French

Buttigieg’s election brought with it the promise of a South Bend that would pencil out—that city government would be run with technocratic efficiency by a local boy who had gone off to Harvard, Oxford, and McKinsey and returned with data-driven wisdom. He campaigned on a platform to revitalize South Bend’s economy, which had been slowly collapsing for 50 years, ever since Studebaker, once the country’s fourth-largest automaker, closed its factory in town in 1963.

In the following decades, offshoring and other structural changes turned the nation’s thriving manufacturing centers, from central Pennsylvania to western Illinois, into the Rust Belt. South Bend, 90 miles east of Chicago, oxidized more than most: Population and per-capita income declined, and in 2011, Newsweek named South Bend one of America’s 10 "dying cities.”

The city is making its way out of its rust-belt past, but progress is incremental Lyndon French Lyndon French

Buttigieg brought data, flow charts, and McKinsey-esque analysis to city government—as well as a bit of philosophical humanism. Since he became mayor seven years ago, unemployment in the city has fallen, from 13 percent in 2010 to 3.2 percent last fall—below the national rate—and South Bend has seen its first significant population increase in half a century. (Unemployment has since ticked back up, to 4.3 percent.)

The country itself was in recovery from the Great Recession during those years, but Buttigieg undertook specific changes that pushed South Bend up the hill. Part of the old Studebaker site is now home to a data-storage and analytics firm; Buttigieg invested city dollars in transforming its largest factory—the prosaically named edifice known as Building 84—into 800,000 square feet of offices where tech and biotech companies are now headquartered. Other former factories are being converted to apartments, and downtown has seen its first new construction in almost 30 years.

In the lobby of Building 84, where new enterprises are emerging, the glory days of its past as a Studebaker plant are still celebrated. Lyndon French

The day before I met Buttigieg, in December, he announced he would not be running for a third term as mayor. Everyone in town knew what that meant for the man President Obama had named as one of the hopes for the future of the Democratic Party: Five weeks later, he launched a presidential exploratory committee and has since been spending little time in South Bend.

Instead, he has been in Iowa speaking to small groups in living rooms, appearing in Austin where he was greeted by hipsters at South by Southwest, and making the interview rounds on television, podcasts and with national publications. (The first topic is invariably how to say his name—"BOOT-edge-edge” or “Buddha-judge.”) His televised appearance on a CNN town hall in mid-March sparked the current boom of Buttigieg enthusiasm.

He’s getting more social media engagement than the other Democratic candidates and recently announced that he’d raised $7 million in campaign donations. That’s a long way from Bernie Sanders current haul of $18 million, but quite a showing for the mayor of a mid-size Midwestern city.