MILWAUKEE — Senator Vance, in his acceptance speech for the vice presidential nomination Wednesday night, said President Trump and his America First movement are the “last, best hope” for this country, and demanded a socially conservative, protectionist new deal for the heartland.

The 39-year-old’s sermon signals not only what a debate with Vice President Harris may look like next month, but what Mr. Vance’s own presidential nomination acceptance speech may look like four years from now. 

Mr. Vance is the youngest vice presidential candidate of a major party since 1952, and has made his bones as a populist, socially conservative legislator in less than 18 months. His memoir and political manifesto, “Hillbilly Elegy”, gave some insight into his policy prescriptions for America, but his speech to the Republican convention on Wednesday solidified his place as the leader of the MAGA movement going forward. 

Mr. Vance hailed “the autoworker in Michigan”, “the factory worker in Wisconsin”, “the energy worker in Pennsylvania and Ohio”, and “single moms like mine” as the true heart of America, instead of the corporate bosses and lobbyists who, he says, have dominated conservative politics for the last half-century. 

The senator called for voters to “fight for America”, highlighting the recent assassination attempt of Trump, praising his boss for raising his fist in the wake of being shot. “Even in his most perilous moment, we were on his mind. His instinct was for us, for our country,” Mr. Vance said. 

After delivering remarks on the would-be assassin that were added after Saturday’s events, Mr. Vance laid out his own more intellectual case for Trumpism and the America First movement — a case that could easily be delivered at the 2028 GOP convention when a potential Vice President Vance is elevated to the top slot. 

During President Biden’s five-decade Washington career, “in states all across our country, jobs were sent overseas, and our children were sent to war,” Mr. Vance said. “President Trump knew even then that we would need leaders who would put America first.”

“Our country was flooded with cheap Chinese goods, with cheap foreign labor, and in the decades to come, deadly Chinese fentanyl. Joe Biden screwed up, and my community paid the price,” the senator said, referring to his southern Ohio roots — a region that has, in recent decades, been devastated by emptied factories and drug use. 

Throughout Mr. Vance’s speech, he spoke of those “who built this country” — those who, he says, were left behind by the trade deals of the 1990’s and early 2000’s and were abused by corporations who were seeking cheap labor beyond America’s shores. 

“We need a leader who’s not in the pocket of big business, but answers to the working man — union and non-union alike,” Mr. Vance said of his running mate. “A leader who won’t sell out to multinational corporations, but will stand up for American companies and American industry. A leader who rejects Joe Biden and Kamala Harris’s ‘Green New Scam’ and fights to bring back our great American factories. We need President Donald J. Trump.”

Mr. Vance leaned heavily into his history as a poor child from Appalachia during his speech, explaining to the American people what it was like to grow up in one of the so-called forgotten communities left behind by globalization and the offshoring of jobs. 

“Every now and then, I will get a call from a relative who asks: ‘Did you know so-and-so?’” Mr. Vance said. “I’ll remember a face from years ago, and then I’ll hear they died of an overdose. As always, America’s ruling class wrote the checks. Communities like mine paid the price.”

It is Trump, however, that can reverse that trend of small-town America paying the price, Mr. Vance argues. “President Trump represents America’s last, best hope to restore what, if lost, may never be found again” Mr. Vance said, quoting President Lincoln. “A country where a working-class boy, born far from the halls of power, can stand on this stage as the next Vice President of the United States of America.”