Democratic presidential candidates former Vice President Joe Biden, and Sen. Elizabeth Warren, D-Mass., shake hands on stage Friday, Feb. 7, 2020, before the start of a Democratic presidential primary debate hosted by ABC News, Apple News, and WMUR-TV at Saint Anselm College in Manchester, N.H. (AP Photo/Charles Krupa)
Elizabeth Warren endorsed Joe Biden on Wednesday, becoming the last of the former vice president's major Democratic presidential rivals to formally back him.
The Massachusetts senator dropped out of the race last month, shortly after a disappointing third-place finish in her home state. She refused to immediately endorse Biden or her fellow progressive Bernie Sanders.
Sanders, who suspended his campaign last week, endorsed Biden on Monday, A day later, former President Barack Obama announced his public backing of Biden.