US Senator Elizabeth Warren endorsed former Vice President Joe Biden for president on Wednesday, giving the presumptive Democratic front-runner another high-profile backing from one of his former rivals.
"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," Warren wrote in a tweet. "Today, I'm proud to endorse Joe Biden as President of the United States."
Warren, a liberal who ended her own bid for the White House last month, gives Biden his third major endorsement of the week, as he looks ahead to November's contest with Republican President Donald Trump.
Biden's chief rival, Bernie Sanders, endorsed him on Monday after suspending his campaign last week, while former President Barack Obama backed Biden on Tuesday.
Like Sanders' endorsement, Warren's support for Biden could help him make inroads with the party's left wing.