Sanders said that while Biden will be the nominee, he will stay on the ballot to collect delegates for the convention, "where we will be able to exert significant influence over the party platform.”

As recently as Monday, his team told aides it was looking for a regional delegates coordinator, according to an internal email.

By dropping out of the race, Sanders is forgoing any effort to soldier on purely as a movement candidate for his progressive agenda. That prospect — though appealing to many of his most ideological supporters — appeared to dim recently amid the deadly coronavirus outbreak, which has shut down campaign rallies, delayed upcoming primaries and consumed the public’s attention.

“Bernie has put his heart and soul into not only running for president, but for the causes and issues he has been dedicated to his whole life. So, I know how hard a decision this was for him to make — and how hard it is for the millions of his supporters — especially younger voters — who have been inspired and energized and brought into politics by the progressive agenda he has championed,” said Biden in a statement. “Bernie has done something rare in politics. He hasn’t just run a political campaign; he’s created a movement.“

Sanders’ withdrawal marks the culmination of one of the most dramatic turnarounds in presidential primary history, with the Vermont senator on the losing end. A month and a half ago, Sanders appeared in control of the nominating contest, coming off early victories in New Hampshire and Nevada.

But Biden’s victory in South Carolina led rank-and-file voters, and a number of former rivals for moderate support in the Democratic primary, to coalesce around the former vice president, who drubbed Sanders in 10 of 14 states on Super Tuesday and nearly all of the states that came later in March, including a three-state sweep — Arizona, Florida and Illinois — as well as the critical general-election state of Michigan. His withdrawal came a day after the Wisconsin primary, whose result has not yet been announced but was expected to be bad for Sanders.