WASHINGTON — Former Mayor Pete Buttigieg plans to endorse former Vice President Joseph R. Biden Jr. in the Democratic presidential race, according to a person informed of the decision, as the Democratic Party’s moderate wing quickly began coalescing around Mr. Biden in an effort to stop Senator Bernie Sanders from winning the Democratic nomination.
Mr. Buttigieg’s endorsement, which is set to come at a Biden campaign event Monday night in Dallas, follows the news that another moderate candidate, Senator Amy Klobuchar of Minnesota, was quitting the race and throwing her support to Mr. Biden. She also plans to back Mr. Biden at the Dallas event. Harry Reid, the former Senate majority leader, was also among those who endorsed Mr. Biden on Monday.
Mr. Buttigieg, the 38-year-old former mayor of South Bend, Ind., sought to portray himself as an agent of generational change, his presence in the race an implicit argument against Mr. Biden and Mr. Sanders. But he rarely had a cross word to say about the former vice president, and in September pivoted his campaign to the center, making ever more forceful arguments against the progressive candidacies of Mr. Sanders and Senator Elizabeth Warren of Massachusetts.
Mr. Buttigieg, who as a candidate led the criticism that Mr. Sanders was too far left to defeat President Trump, is throwing his support to Mr. Biden at a time when establishment Democrats are alarmed that moderate voters are too divided to stop Mr. Sanders, and fear his nomination would jeopardize Democrats’ House majority and many state-level elections.
Mr. Buttigieg won 26 delegates over the course of the first four early states, a number that would be inconsequential in all but the closest of convention fights. His biggest value to Mr. Biden may be in his ability to transfer some or most of his vaunted fund-raising apparatus to the former vice president. Mr. Buttigieg raised more money than did Mr. Biden in each fund-raising period of 2019, despite beginning his campaign as a virtual unknown in national politics.
Within hours of Mr. Buttigieg’s withdrawal, staff members for Mr. Biden’s campaign began courting Mr. Buttigieg’s donors and fund-raisers. Some, like Representative Don Beyer of Virginia, swiftly announced their new allegiance to Mr. Biden. Others who had spent recent weeks privately trashing Mr. Biden as too old to defeat President Trump in a general election, said they were likely to eventually move to back Mr. Biden but would not do so right away.