“This is not,” President Biden often says with sinister undertones, “your father’s GOP.” Yet as Republicans trot out their vice-presidential nominee, Senator Vance, they’re offering a sunnier face to America, usurping the pandering, patrician leaders of their past in hopes of victory.

“Tonight is a night of hope,” Mr. Vance said. He hewed to that theme throughout a speech heavy on aspiration and light on polarizing policy. He didn’t play the usual vice-presidential role of attack dog, baring his teeth only to smile.

It’s hard to imagine a previous Republican candidate referring, as Mr. Vance did, to his “mamaw … the name we hillbillies gave to our grandmothers,” much less the crowd responding with cheers and “mamaw” chants. It turns out that the “Hillbilly Elegy” author knew his audience.

Mr. Vance praised “hardworking people” in his native Appalachia, “coal country,” and “small towns like mine.” He used “Democrat” only once. “I pledge to every American,” he said, “no matter your party, I will give you everything I have to serve you.”

President Trump, Mr. Vance said, “called for national unity literally right after an assassin nearly took his life.” The 45th  president “is tough … but he cares about people. He can stand defiant against an assassin one moment and call for national healing the next.”

Trailing in the polls, Mr. Biden will have to go on offense at the DNC and raise the issues Mr. Vance avoided. It’ll be a difficult needle to thread. His familiar snarling will come across as divisive after all this talk of unity, which is expected to be a theme of President Trump’s acceptance speech.

“We have a big tent in this party on everything from national security to economic policy,” Mr. Vance said. Republicans have long invoked that metaphor, but Americans who shower after work instead of before, long suspected that butlers were guarding the tent’s flaps. 

Instead of legacies, viewers were treated to everyday people like Mr. Vance’s wife, Usha Vance, wearing light makeup, wisps of hair flowing. She recounted the Marine’s courtship, teased him about his beard — he’s the first candidate with one since 1892 — and spoke of how he’d learned to cook Indian food for her immigrant parents.

If a spouse’s job is to gaze lovingly, Mrs. Vance ranked with First Lady Nancy Reagan, who was often mocked for mooning over her “Ronnie.” The old guard would’ve clucked its tongues at this come-as-you-are, hillbilly convention, the way they did over President Reagan having gone to Eureka College instead of the Ivy League.

Reagan delivered, so the GOP tolerated the rural and “too religious,” pro-life evangelical and pro-Israel voters who loved him.

Trump and Mr. Vance have forged a new GOP. It has the I-beams of Reagan and President Eisenhower, reared in rural Kansas. “The proudest thing I can claim,” Ike said, “is that I am from Abilene.”

Republican conventions once lacked minorities. This one had speakers ladled straight out of the melting pot and their proudest boast was to be American. “The only colors that matter in the foxhole,” the Florida congressman and Green Beret, Michael Waltz, said in his speech, “are the red, white, and blue, baby.” 

A graphic on MSNBC of “Notable Republicans Not Attending the RNC” showed President George W. Bush, Congresswoman Liz Cheney, and Senator Romney, all children of GOP powerbrokers. Vice President Pence was also pictured.

Speaker Ryan, remembered by conservatives for rolling over in his debate with Mr. Biden, then vice president, in 2012, rounded out the graphic. He and the others were watching from home, as were Vice Presidents Cheney and Quayle. No members of previous Republican tickets were present.

Without them looking on, Mr. Vance was free to criticize Mr. Biden for supporting “the disastrous invasion of Iraq” and describe the suffering he witnessed from the Great Recession, NAFTA, trade deals with Communist China, and the housing crisis.

Mr. Vance could zing “the ruling class,” because its Republican members packed up and went home. This RNC announced a new reality. The right won’t defend or embrace the Bushes, Cheneys, and Romneys any more than the left, however Mr. Biden pretends to miss them.

It’s noteworthy that one of the few GOP warhorses at Milwaukee was Speaker Gingrich, himself a rebel against the party establishment. When Mr. Vance said, “We’re done catering to Wall Street; we’ll commit to the working man,” he echoed the Republican revolution of 1994 that Mr. Gingrich led.

Mr. Vance, with his performance, gave voice to the working Americans and those who show up at houses of worship for more than weddings and funerals. The old guard, which believed that such voters were best kept quiet, were mere ghosts at the RNC, and the new GOP cheered as the senator buried them with his hillbilly elegy.