The hotly contested five-way primary was an early show of Trump’s power as kingmaker.
Over $70 million was spent on TV ads during the primary campaign as multiple candidates claimed they were the only true pro-Trump candidate in the race, according to NBC News.
Trump’s endorsement came late in the game, over a week after early voting had started. It evidently made a difference, as Election Day ballots skewed more toward Vance than early ballots.
“I couldn’t be happier about J.D.’s victory tonight,” Donald Trump Jr. said in a statement to NBC. “J.D. represents a new generation of conservative fighters in the vein of my father who understand that the time for talking is over, and the time for getting things done is here.
Vance will face off against Democratic Representative Tim Ryan in November.
Republicans are favored in the general election as polling suggests Ohio has shifted right in recent years.