Representative Dean Phillips of Minnesota, a Democrat who began a long-shot primary challenge to President Biden last month, said on Friday that he would not run for re-election next year.
Mr. Phillips, 54, a moderate third-term congressman who represents a district that includes suburban Minneapolis, renewed his call for generational change in Washington as he announced the move.
“After three terms it is time to pass the torch,” he said in a statement, describing a country “facing a crisis of cooperation, common sense and truth.”
In challenging Mr. Biden for the Democratic nomination, Mr. Phillips has cited the president’s age, 81, and his low approval ratings, warning that Mr. Biden risks losing his re-election bid to former President Donald J. Trump, 77, the Republican front-runner. Recent polls, including a New York Times/Siena College survey, have shown Mr. Biden trailing Mr. Trump in key battleground states.
But Mr. Phillips has little chance against Mr. Biden as the race currently stands, with the Democratic Party and major liberal donors firmly lined up behind the president.
Mr. Phillips has also angered Democrats with his criticisms of Mr. Biden, and he recently walked back comments he made questioning the capabilities of Vice President Kamala Harris.
His presidential campaign’s early focus on heavily white New Hampshire has drawn criticism from Black Democrats in particular.
Representative James E. Clyburn of South Carolina, the influential Democrat who played a key role in Mr. Biden’s 2020 ascent, wrote on social media that Mr. Phillips was “not respecting the wishes of the titular head of our Party and the loyalties of some of our Party’s most reliable constituents.”
Mr. Phillips, the heir to a Minnesota liquor company who also ran the gelato company Talenti, has already used some of his fortune to fund his presidential campaign.
Since he won election in 2018, his congressional district has been a relatively safe Democratic seat: He was re-elected last year with 60 percent of the vote.
