“We are going to break up the big tech companies, ladies and gentlemen, we have to do it,” J.D. Vance hollered at a rally for Donald Trump in Ohio last weekend. “You cannot have a real country if a bunch of corrupt scumbags who take their marching orders from the Communist Chinese tell us what we’re allowed to say and how we’re allowed to say it.”Mr. Vance, a 37-year-old memoirist and venture capitalist who is running in the Republican Senate primary in Ohio, is new to politics. But he was recently fortified by Mr. Trump’s endorsement in a hotly contested race, and his language on that bright and breezy afternoon was suitably bold.Amid a nodding crowd of men and women in Trump T-shirts and MAGA hats, Mr. Vance’s gray suit may have looked a bit funereal, but his applause lines were decidedly un-stodgy. He assailed Joe Biden as a “crazy fake president who will buy energy from Putin and the scumbags of Venezuela but won’t buy it from middle class Ohioans,” who live in a top fracking state.Donald Trump told a frenzied crowd in Ohio in April that J.D. Vance was a “fearless MAGA fighter.”“Scumbag” is a word that seems to have entered Mr. Vance’s public vocabulary only recently. It didn’t appear in “Hillbilly Elegy,” the tender 2016 autobiography in which he described his clannish and troubled Kentucky-descended family.Ohio hillbillies — some of them natives, some of them migrants from Kentucky and West Virginia who manned Ohio’s factories in the last century — are Mr. Vance’s people. He wrote about them in his memoir without condescension or squeamishness: his drug-addicted and erratic mother, who asked him for a cup of his clean urine one morning when she expected to be drug-tested at work; the various boyfriends, husbands, police officers and social workers her misadventures brought into the family’s life; his tenacious grandmother Mamaw, who, as he recalled more recently, “loved the Lord” and “loved the F-word” and owned 19 handguns.These people helped him on his way from the blighted Ohio steel town of Middletown to the Marines, Ohio State and Yale Law School.A television ad for J.D. Vance’s Senate campaign.Published on the eve of the 2016 elections, “Hillbilly Elegy” made Mr. Vance, then 31, a literary sensation. It sold more than three million copies, and is still a staple of high school and college curriculums. Pundits most likely speed-read the book for its sociological “takeaway,” a description of the left-behind whites who then seemed instrumental in rallying the Republican Party behind Mr. Trump and would soon put him in the White House.While the author of “Hillbilly Elegy” retained a lot of the exotic patriotism of his kinfolk, even to the extent of choking up whenever he heard “Proud to Be an American,” he drew the line at their chosen candidate. In spirited interviews, articles, tweets and text messages throughout the 2016 election season, Mr. Vance described Mr. Trump as “reprehensible” and an “idiot.” He didn’t vote for him. Many of Mr. Vance’s cosmopolitan literary admirers must have been consoled to think that discerning citizens could see through Mr. Trump, even in the parts of the country most taken with him.But Mr. Vance backed Mr. Trump in 2020. And now, a week before the Republican primary on May 3, Mr. Trump has traveled to Ohio to tell a frenzied crowd that, even though Mr. Vance once said a lot of nasty things about him, he is a “fearless MAGA fighter” and “a great Buckeye.” And here comes Mr. Vance, bounding onstage to call Mr. Trump “the best president of my lifetime.”Mr. Vance’s readers may feel let down and misled. So too, in their own way, may his Republican primary rivals in Ohio, who have been professing their fidelity to Trumpism, only to see their leader confer his blessing on a Johnny-come-lately. The conservative Club for Growth, which backs the former Ohio treasurer Josh Mandel, has spent millions on campaign ads that replay every Trump-skeptical thing Mr. Vance said half a decade ago. When Mr. Trump’s endorsement of Mr. Vance was first rumored, dozens of Mandel allies even petitioned the ex-president to reconsider.Fans of “Hillbilly Elegy” may feel let down by J.D. Vance’s support for Donald Trump.Mr. Vance’s Trumpian turn has left a wide variety of people wondering whether it arises from sincere conversion or cynical calculation. But there is something more complex going on.Readers of “Hillbilly Elegy” who find Mr. Vance’s campaign rhetoric a jarring departure may actually be misremembering the book. His Mamaw railed at the so-called Section 8 federal subsidies that allowed a succession of poor families to move in next door. Southern whites were migrating to the Republican Party, Mr. Vance wrote, in large part because “many in the white working class saw precisely what I did, working at Dillman’s,” a neighborhood grocery. There, thanks to food stamps, he wrote, “our drug-addict neighbor would buy T-bone steaks, which I was too poor to buy for myself but was forced by Uncle Sam to buy for someone else.”If Mr. Vance and the people who populate his book were bursting with political impulses, they had as yet no political program, so their impulses meant nothing. Before Donald Trump, there was no place in the country’s political imagination — or its heart — for the poor whites he described. Mr. Trump changed that — nowhere more so than in Ohio. A lot of political gestures today don’t have the same meaning that they did five years ago.J.D. Vance is new to politics. But he was recently fortified by Donald Trump’s endorsement.Ohio has produced seven presidents and, until last fall, had a reputation as an electoral bellwether. In the 14 presidential elections between Lyndon Johnson’s victory in 1964 and Donald Trump’s in 2016, Ohio sided with the winner every time. In Joe Biden’s narrow 2020 victory, however, it lurched wildly to Mr. Trump, giving him an eight-point victory in the state. Some states voted more heavily for Mr. Trump, but none has been more transformed by him.Mr. Vance is running for the Senate seat held for two terms by Rob Portman, a Republican who is retiring, and Mr. Trump’s endorsement has been the great prize in the Republican primary. At times the race has seemed less an election than an audition. The various candidates, including Mr. Vance, traveled to Trump’s Mar-a-Lago resort for fund-raisers and consultations and solicited the help of Trump allies and family members. (Donald Trump Jr. was an early Vance backer.)Each of the Republican candidates in the primary has built his or her campaign around an implicit hypothesis about how to appeal to Mr. Trump, and thus about what Trumpism is in the first place. Jane Timken, former chair of the state Republican Party, tried to win over Mr. Trump by hard work and loyalty. In 2017, she led the Trumpian project of breaking then-Gov. John Kasich’s grip on the state Republican Party.The former state treasurer, Mr. Mandel, appears to have been guided by the idea that imitation is the sincerest form of flattery. Having made his name promoting transparency in state accounts and other old-style mainstream Republican priorities, he now torques ordinary conservative dispositions into categorical imperatives. (“I think illegal immigrants should be deported, period,” he said at a debate in March, specifying that he meant “every single illegal.”)Rallygoers joined in the pledge of allegiance.J.D. Vance grew up in Middletown, Ohio.Mr. Vance’s ultimately successful route to Mr. Trump’s favor was a bit subtler. To him the core of the Trumpian project isn’t intraparty power struggles or demagogy; it’s reconnecting politics to ordinary people. Mr. Vance tries to do this in a lot of different ways. For one thing, he calls for breaking up the nation’s cozy political system. After laying out a list of Mr. Trump’s triumphs to the MAGA crowd last weekend, Mr. Vance insisted, “The thing that Trump revealed, more than any policy achievement, is that we are living in an incredibly corrupt country.”What does it mean, Mr. Vance likes to ask listeners, that six of the highest-income ZIP codes in the United States are in metropolitan Washington? How do legislators get so rich on the relatively modest salaries they make?Mr. Vance also grasps, as Mr. Trump does, the deep discontent with political correctness, and the hunger for someone unafraid to stand up to it. If there was a moment in Mr. Vance’s campaign where his fortunes seemed to turn it was his release of a TV ad that began: “Are you a racist? Do you hate Mexicans? The media calls us racist for wanting to build Trump’s wall.”The ad took voters by the collar. The sense among Ohioans at town halls that they are being cast as “bad people” for holding contestable but reasonable political views is palpable. They have reason to think their lives and careers can be damaged by the merest imputation of racism. A person like Mr. Vance who is willing to crack a joke about the term “racist” is someone fearless enough to follow into battle.From Mr. Trump’s perspective, it cannot have harmed Mr. Vance that he was willing to burn his boats this way. Donald Trump Jr., traveling with Mr. Vance in the week his father endorsed him, drew a contrast between Mr. Vance and other Republicans who “crumble the moment the media falsely accuses them of being ‘racist.’”Donald Trump Jr., here in Ohio with J.D. Vance, was an early backer.The barrage of televised attacks on Mr. Vance for his previous anti-Trump remarks may even have provided him with a Trumpian credential, as one who can handle nonstop negative publicity. This is not to say that Mr. Vance lacks his own formidable supporters: Peter Thiel, a Trump supporter in 2016 and a Vance friend, has reportedly made $13.5 million in campaign contributions to Protect Ohio Values, a Super PAC backing Mr. Vance.The ads that were meant to deny Mr. Vance the Trump endorsement set up an institutional confrontation that may also have worked in his favor. The Club for Growth, the Washington-based anti-tax group backing Mr. Mandel, was responsible for the ads exposing Mr. Vance’s anti-Trump remarks in 2016. But back then the Club itself was among the most Trump-hostile of Republican groups.It continues to pursue a largely supply-side, limited-government, free-trade agenda, at a time when the Trumpified Ohio G.O.P. has grown so suspicious of corporate progressivism (or, if you will, “woke capital”) that it distrusts even the Chamber of Commerce. Mr. Vance’s aides took to calling Mr. Mandel’s backers “The Club for Chinese Growth.”Then one day about two weeks ago, Mr. Vance was having a milkshake with his son when his phone rang and a voice on the other end said, “Hey, this is Donald Trump.”Mr. Vance himself has a theory about why he got the Trump endorsement and his rivals did not. It is that he treated Mr. Trump not just as a person to be flattered or parodied but also as the source of an actual political program to be carried out.“A mistake that a lot of the other guys made is that they think that ‘America First’ is a slogan or a talking point,” he told the Dayton reporter Chelsea Sick recently. “But there’s actually a substantive agenda behind it.”Whether globalization has been good or bad is not a complicated question for most Ohioans. That agenda involves trade policy, drug policy, securing the Mexican border and steering clear of unnecessary foreign wars. Some of the other candidates were unaware of how seriously Mr. Trump takes those things.“He’s a smart guy,” Mr. Vance continued. “So, unfortunately, you can’t just say nice things about Donald Trump in public. You actually have to align yourself with an agenda.”The heart of that agenda is resistance to globalization. If you wanted a one-word answer to why Mr. Trump has so rocked Ohio politics it would be: Nafta. The North American Free Trade Agreement of 1993 remains a symbol of the institutional adjustments that, over the course of a generation, turned the United States from a manufacturing economy into a service economy.Whether free trade and globalization have been good or bad for the United States is a complicated, multivariate calculation. But it is not complicated for most Ohioans. The state’s manufacturing power was once so prodigious that you almost suspect you’re reading typos when you see it quantified: Did G.M. really more than 16 million Chevy Impalas and Pontiac Firebirds and other models at its Lordstown plant in the Mahoning Valley between 1966 and 2019, when the plant ceased production? Did the Lorain works, an hour and a half away, really produce 15 million Ford Fairlanes, Mercury Cougars and so on, between the Eisenhower administration and 2005?Simply scuppering the infrastructure that made such achievements possible — along with the decent-paying jobs that knit together the whole culture of the state — looks profligate to Ohio eyes. Each of these plants also had a constellation of businesses around it, some small but others vast. Armco, where J.D. Vance’s grandfather worked, rolled steel for automobiles.This is by now an old story, but in Ohio the arrival of Donald Trump has made it a thoroughly different story. For three decades after Nafta passed, no major-party presidential nominee dared raise his voice against it — until Mr. Trump, who had always railed at Nafta, came along.As long as the state’s main grievance was closed to debate, the essential conservatism of the state’s electorate was hidden under a blanket of apathy and cynicism. For a while, Democrats alone voiced misgivings about globalization — Representative Marcy Kaptur in her lakefront district; Senator Sherrod Brown; and Representative Tim Ryan, the likely Democratic candidate for the seat Mr. Vance is contesting. That made conservative Ohio look like more of a swing state than it actually is.Whether Mr. Trump effectively stopped anything related to globalization can be debated. But his arrival on the scene was, for Ohioans, an electroshock, a vindication, a license for rebellion.MiddletownMarionInterstate 71, outside ColumbusSheffieldMr. Vance can be expected to have a feel for this. As he often says on the campaign trail, the decline of Middletown coincides with his lifetime. At a campaign event in Beavercreek, near Dayton, Kim Guy, a retired nurse, stopped at the front door before leaving and patiently explained why she was supporting Mr. Vance. She didn’t mention this or that policy or whether his change of heart was credible. “He lived it,” is the main thing she said. “He had to get down to ramen noodles the last week of the month. The rice with warm milk. He lived it.”A Vance supporter at the recent Trump rally.A home near the steel mill in Middletown.Before Mr. Trump’s arrival on the scene, Mr. Vance’s hillbillies fit poorly into the prevailing political framework for helping the downtrodden. Perhaps those people could be seen as another of the inexplicably overlooked minorities who, in the half-century since the Civil Rights Act of 1964, have from time to time come to the country’s attention — a kind of mission land to which the newest gospel of compassion, progress and rights hadn’t yet spread.But that perspective was always distant from the way Mr. Vance saw the world. “A compassion that assumes a person is disadvantaged to the point of hopelessness is like sympathy for a zoo animal,” he wrote in the Catholic journal The Lamp in 2020, “and I had no use for it.”Events since 2016 have presented Americans with another option — a Republican Party reoriented around the priorities of Donald Trump. Mr. Vance does not look out of place in the heart of that party. In early April he was the only candidate to win the endorsement of Ohio Right to Life, an anti-abortion activist group. Representative Marjorie Taylor Greene, the often outlandish Republican of Georgia, endorsed him, too. Asked at a debate to disavow her, Mr. Vance replied that he would not, because he had been taught that you shouldn’t “stab your friends in the back.”That kind of talk is all over “Hillbilly Elegy.” It is practically his Mamaw’s philosophy of life.At his appearance in Beavercreek, Mr. Vance spoke about his mother, clean for seven years, and how the fentanyl on today’s streets might have killed her had she still been using. Eventually he would get around to denouncing the “nonstop violence, sex-trafficking and drugs” at the Mexican border and calling for the building of Mr. Trump’s wall, but for a moment his conversation took on a softer note.“I love this country,” he said. “I love that it’s not just a country for everybody who does everything right, but it’s also an America for the giving of second chances. It’s for people who keep getting back on the horse.”No state has been more transformed by Donald Trump than Ohio has.It can be difficult, even disorienting, to think of Donald Trump as having provided certain Americans with recognition, a second chance, a possibility of renewal. But he has. A politics that was unavailable has been made available. Under such circumstances accusing Mr. Vance of not backing Trumpism during the Obama administration is like accusing someone of not backing the New Deal during the Hoover administration or not backing gay marriage during the Reagan administration.Mr. Vance’s liberal admirers and conservative opponents are not wrong to feel that something has changed since his book came out in 2016. But it isn’t Mr. Vance. It’s the country.The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram. More