Sen. Elizabeth Warren, D-Mass., endorsed presumptive Democratic nominee Joe Biden for president Wednesday.
"We're all in this together now," Warren said in the Twitter announcement. "And now, it's up to all of us to help make Joe Biden the next president of the United States — let's get to work."
Biden and Warren have not always seen eye-to-eye on key issues. The former vice president accused her of being an "elitist" in a November essay published in Medium which attacked the senator for allegedly painting Democrats who disagree with her in a negative light.
"Some call it the 'my way or the highway' approach to politics," Biden wrote. "But it's worse than that. It's condescending to the millions of Democrats who have a different view. It's representative of an elitism that working and middle-class people do not share: 'We know best; you know nothing.' 'If you were only as smart as I am you would agree with me.'"
Warren, meanwhile, opposed Biden over the issue of bankruptcy reform legislation when she was a Harvard professor and he was a senator from Delaware. Biden consistently supported measures would make it difficult for average families to file Chapter 7 bankruptcy protection, including the 2005 Bankruptcy Abuse Prevention and Consumer Protection Act, which was eventually signed into law by former President George W. Bush.
However, each candidate has also spoken positively about the other in the past. Warren defended Biden's lawfulness after he made comments suggesting that he might not comply with any lawfully-issued Senate subpoena during President Donald Trump's impeachment trial. Trump and his supporters claimed that Biden pressured Ukraine into firing a prosecutor named Viktor Shokin for investigating alleged criminal activity by his son while he was vice president. Trump was impeached in December after it was revealed that he withheld $391 million in military aid to Ukraine as he sought investigation into the Bidens. No credible evidence supports that claim.
"Donald Trump is being impeached for abuse of power, and that's where our focus should be. Shame on him for trying to switch this over to something else," Warren told reporters in December when asked about the subpoena issue. "But Joe Biden has said that he has always abided by every lawful order, and if there's a lawful order on a subpoena, then I assume he would follow it."
She added, "Right now, we should be focusing on the subpoenas that have already been issued, for [former White House counsel] Don McGahn and for [acting White House Chief of Staff] Mick Mulvaney, who have first-hand knowledge of what the president did. That's where the testimony should come from in this impeachment trial, but that's the part that [Senate Majority Leader] Mitch McConnell and the president just don't want to put out there in public, and that's wrong."
Biden told Axios the same month that he would consider choosing Warren as his running mate if he won the Democratic presidential nomination.
"I'd add Senator Warren to my list. I'd add all — But she's going to be very angry at my having said that. The question is: 'Would she add me to her list?'" Biden asked Axios' Mike Allen.
Biden said in the interview that "the reason I was reluctant to mention anyone is because . . . it is presumptuous of me to decide who I'd have as a vice president. I'm not even the nominee yet — that's No. 1."