Klobuchar, the senator from Minnesota, faced a tough night on Super Tuesday, including the possibility of losing her home state’s primary to Bernie Sanders.
She was among a group of moderates who sought the nomination, but her prospects dimmed after poor showings in the Nevada caucuses and the South Carolina primary. The high point of her campaign was New Hampshire, when she placed third after delivering a standout debate performance only days earlier.
Pete Buttigieg, the former mayor of South Bend, IN, ended his presidential bid on Sunday but has yet to endorse in the race.
Klobuchar’s exit from the race means that none of the major Democratic party contenders are younger than 70. Biden, Sanders, Mike Bloomberg and Elizabeth Warren remain. Tulsi Gabbard, a congresswoman from Hawaii, also is in the race, but she has trailed in the polls and the primaries so far.
On Monday, Biden also picked up the endorsement for Harry Reid, the former Senate majority leader.