Mr. Presley, 45, is one of three elected members of the state Public Service Commission, which regulates utilities, and is the former mayor of Nettleton, a small town in the bright-red northeast section of Mississippi. He talks energetically about the need to expand Medicaid and save rural hospitals, and why it’s important to eliminate the extremely regressive state grocery tax, and would rather discuss the lives of poor families than his own family ties to a certain popular singer of the same last name from Tupelo, up the road from Nettleton. (Elvis was his second cousin.)

His most effective tactic is his unrelenting attack on Mr. Reeves and the welfare scandal that has swirled around him and the previous Republican governor, Phil Bryant. A 2020 state audit found that as much as $94 million in federal anti-poverty money was improperly diverted to two nonprofit groups that used it for favors to lobbyists, celebrities and some lawmakers. The celebrities included Brett Favre, the former N.F.L. quarterback, who, according to text messages uncovered by the nonprofit news site Mississippi Today, arranged to spend $5 million in welfare funds for a volleyball stadium at the University of Southern Mississippi, his alma mater. At the same time, the state was rejecting a large majority of requests from families for Mississippi’s meager $170 a month in welfare payments.

Mr. Reeves was lieutenant governor when all this was going on, and several people at the center of the scandal have been his friends and supporters. Last summer, his administration fired the lawyer who had been officially assigned to investigate the scandal and recoup the money, after the lawyer issued a subpoena to the university’s athletic foundation regarding the volleyball money. Though Mr. Reeves hasn’t been implicated in the diversion of most of the money, Mississippi Today published text messages in August showing that the former state welfare director, who pleaded guilty to federal and state fraud and theft charges last fall, said he was acting on behalf of Mr. Reeves when he siphoned $1.3 million of the welfare money to a fitness program run by the governor’s longtime personal trainer, Paul LaCoste.

That was all Mr. Presley needed.

“I got in this when I saw, as all Mississippi did, millions of dollars aimed at working families got diverted by Tate Reeves and his cronies,” he told me last week. “His own personal trainer, who taught Tate Reeves how to do jumping jacks, got a $70,000 vehicle and was paid $11,000 a month, while we’ve got children going hungry in Mississippi. Well, it made me want to puke.”

Mr. Presley is funny and garrulous and is often described as the best natural politician in the state, with an easygoing manner that appeals to voters of all types. He grew up as the son of a low-income single mother and speaks with real empathy about the tens of thousands of poor families, Black and white, who can’t get clean drinking water, proper health care or broadband internet after decades of largely racist neglect by the state.