Sen. Elizabeth Warren, D-Mass., endorsed Joe Biden on Wednesday, saying about her former 2020 rival: “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 @JoeBiden as President of the United States,” she said in a tweet.

Warren endorsed Biden, the presumptive Democratic 2020 presidential nominee, the day after former President Barack Obama officially backed his ex-vice president. Obama waited to endorse Biden until Sen. Bernie Sanders, the Vermont independent, quit the race.

Biden now heads into November with the backing of all of his 2020 primary rivals.

Working out of his Delaware home, running a virtual campaign because of the COVID-19 pandemic, Biden has started to vet vice presidential candidates. He pledged to pick a woman to be his running mate, and Warren is on the long list.

Warren started strong in her own presidential bid and then faded as Bernie Sanders prevailed over the progressive wing of which she is a leader. Biden won the primary in Massachusetts even though he barely campaigned there.

Biden, in a statement, showered praise on Warren and said he has been working with her on policy initiatives.

“By centering her campaign in the importance of ideas and comprehensive policy plans, she helped set a high-water mark for what our politics can be at their best — authentic and service-oriented, focused on how we can deliver the most help to the most people. And I’ve been proud to work with her over the past few weeks to identify and adopt important policy proposals that will strengthen us as a people.

“At a moment of crisis for our nation, Senator Warren’s ideas will be more important than ever as we chart a path forward.”

Biden added, Warren “knows what’s possible when leaders put their own egos aside and do the work.”

Warren still has a strong following.

Warren followed up with another tweet asking her followers to donate to Biden’s campaign.

“Now it’s up to all of us to help make @JoeBiden the next president. Let’s get to work. Go to http://JoeBiden.com right now, and chip in your $5, make some calls, send some texts — because we are all in this together.”

The Biden campaign has been steadily rolling out endorsements the Biden team has been banking in order to give folks their day and to maximize the message.

Also Wednesday, endorsements from senators from two key swing states, Wisconsin and Michigan, were announced by the Biden campaign.

Sen. Tammy Baldwin, D-Wis., endorsed Biden, as did Michigan Sens. Debbie Stabenow and Gary Peters.

Baldwin said in a in a statement, “I’m supporting Joe Biden for president not just because he’s always fought for the bold, progressive change that working families in Wisconsin need — but because he understands that everyone deserves to be treated with dignity and respect — and afforded the opportunity to thrive. The road to the White House goes right through Wisconsin and I’m going to do everything I can to make sure Joe Biden wins here in November. And I hope you’ll join me.”

Stabenow said in a statement, “Joe Biden has always had our backs in Michigan.”

He added: “Time after time, he has been there for us when it really counted. Whether it’s standing with our auto industry during the 2009 crisis, protecting our Great Lakes or making sure people have health care, Joe Biden understands our Michigan way of life. I’m honored to call Joe my friend. I’ve worked with him as a colleague in the U.S. Senate and as Vice President and have seen first-hand how he puts workers and their families first every day. For these reasons and so many more, I enthusiastically support Joe Biden to be our next President of the United States. And, I am committed to working hard to achieve his victory. I am confident the people of Michigan will be there for him in November just as he has always been there for us.”