RALEIGH, N.C. — Representative Madison Cawthorn has conceded to a North Carolina state senator, Charles Edwards, in the Republican congressional primary.

A spokesman for Mr. Cawthorn’s campaign, Luke Ball, told the Associated Press late Tuesday that Mr. Cawthorn had conceded the race. A fast-food franchise owner, Mr. Edwards now advances to the November election against Democrat Jasmine Beach-Ferrara.

Mr. Cawthorn failed Tuesday to hold on to his western North Carolina seat, facing a stiff challenge from a state legislator in the Republican primary.

Six other GOP candidates were in the race, which became a test of whether voters would grant Mr. Cawthorn another term despite his personal and political stumbles.

Several GOP leaders have turned away from the 26-year-old congressman, with some citing a series of unforced errors, such as calling the Ukrainian president a “thug” after Russia invaded his country. Mr. Cawthorn also infuriated fellow Republicans in Congress when he alleged on a podcast that he had been invited to an orgy in Washington.

Mr. Cawthorn has banked on his successful fundraising, social media presence, and vocal support for the former president, Donald Trump, to help him win the 11th Congressional District nomination again.

Mr. Edwards, an owner of McDonald’s franchises, received endorsements from Senator Tillis of North Carolina and the state’s top GOP legislative leaders. A super PAC allied with Mr. Tillis ran ads against Mr. Cawthorn, one of which called him a “reckless embarrassment” and “dishonest disaster.”

Within days of taking office in early 2021, Mr. Cawthorn spoke at the “Stop the Steal” rally questioning President Biden’s presidential election victory that preceded the January 6 Capitol insurrection. Mr. Cawthorn soon became a leading spokesperson for Mr. Trump’s “America First” policies and conservatives in the culture wars. Mr. Trump has endorsed him.

Besides the remark about being invited to an orgy, Mr. Cawthron said he had seen leaders in the movement to end drug addiction use cocaine. Minority Leader McCarthy reprimanded him publicly for the remarks.

Mr. Cawthorn has been stopped by police on driving citations three times since October and caught with guns at airport checkpoints twice since last year, including last month. And videos released in the campaign’s final weeks showed Mr. Cawthorn in sexually suggestive poses, which he said were from several years ago — meant to be funny and nothing else.

Mr. Cawthorn acknowledged speeding and gun citations as failings, but said the videos were part of a “drip campaign” by his political enemies, of which he has included some Republicans, to flood the district with negative stories.

Mr. Cawthorn was seen as a rising star by many conservatives when in 2020 he won a primary runoff for the seat being vacated by Mark Meadows, Mr. Trump’s chief of staff.

Mr. Cawthorn, who uses a wheelchair after being partially paralyzed from a car accident as a teenager, turned 25 — the constitutionally mandated minimum age to serve in the House — during the 2020 campaign.

In an election-eve post on his social media site Truth Social, Mr. Trump asked primary voters to back him again: “Recently, he made some foolish mistakes, which I don’t believe he’ll make again … let’s give Madison a second chance!”

His biggest political mistake may have occurred last fall, when he decided to run for a different House seat that could have led to an easier reelection bid, only to return to the 11th District when redistricting litigation shifted the lines again. Mr. Edwards and others accuse Mr. Cawthorn of trying to walk away from his constituents for political convenience.