WASHINGTON — Elizabeth Warren endorsed Joe Biden on Wednesday and became the latest of the former vice president’s onetime White House rivals to back him as the Democratic Party moves to project unity against President Donald Trump going into the November election.

The Massachusetts senator rose to brief front-runner status in the Democratic race last fall but suspended her campaign last month after a disappointing “Super Tuesday” that included a third-place finish her home state. Warren left the race without immediately endorsing Biden or her fellow progressive Bernie Sanders, but the dynamics changed substantially in subsequent weeks, with the race on hiatus amid the coronavirus outbreak.

Sanders dropped out last week and endorsed Biden within six days, hoping to persuade his fervent progressive supporters to warm to the more centrist Biden. Former President Barack Obama followed suit on Tuesday, and then Warren, in a move that could fuel speculation that Biden may choose her as a running mate.

Warren made no mention of that possibility in announcing her endorsement, instead saying in a statement that Biden "grew up on the ragged edge of the middle class.” That phrase that was a centerpiece of Warren's own campaign and referred to her own upbringing in Oklahoma.

Warren also referred to the pandemic by tweeting: “In this moment of crisis, it’s more important than ever that the next president restores Americans’ faith in good, effective government — and I’ve seen Joe Biden help our nation rebuild. Today, I’m proud to endorse