President Barack Obama endorsed Hillary Clinton Thursday using her own campaign slogan, "I'm with her," uniting two former rivals under one banner in a bid for unity in the Democratic party.
"I know how hard this job can be," Obama says in a video released on her YouTube channel, promising to hit the campaign trail for Clinton soon. "That's why I know Hillary will be so good at it. In fact I don't think there's ever been someone so qualified to hold this office."
The video was posted shortly after Obama met with Clinton's rival for the Democratic presidential nomination, Bernie Sanders. Sanders said Thursday he will contest the final primary, in Washington D.C. on Tuesday, but also said he would work with Clinton to defeat Trump.
Clinton has secured the support of enough delegates to become the Democrats' presumptive nominee. Many other Democratic politicians have endorsed Clinton, including the party's leaders in the House and Senate.
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But Thursday was a milestone for Clinton. Not only did she secure Obama's support, she was endorsed by liberal firebrand Sen. Elizabeth Warren and appeared to get the same from Vice President Joe Biden.
Warren appeared on "The Rachel Maddow Show" to say that she would fight for Clinton to win over Donald Trump. Biden, who once seriously considering running against Clinton and Sanders, said in a speech that "whoever the next President is, and God willing in my view it will be Secretary Clinton," an off-hand remark that amounts to his first endorsement of Clinton.
Obama recalled both Clinton's time as his secretary of state — they decided to kill Osama bin Laden and conducted diplomacy around the world — and the more than 20 debates they took part in during their own "hard-fought campaign" in 2008.
Obama, who had a 88 percent approval rating among Democrats in a May NBC/WSJ poll, appealed to his supporters to back Clinton's campaign for president: "I have seen her judgment, I've seen her toughness, I've seen her commitment to our values up close."
Clinton reacted to the president's endorsement in an article in Bloomberg Politics that said it was timed to the release of the video: "It just means so much to have a strong, substantive endorsement from the president. Obviously I value his opinion a great deal personally."
As the Clinton campaign circulated the Obama video, it announced their first joint appearance on the campaign trail will be Wednesday in Green Bay, Wisconsin. The campaign said Obama and Clinton will discuss building on the progress made during his presidency "and their vision for an America that is stronger together."
Donald Trump, the presumptive Republican nominee for president, reacted quickly on Thursday, tweeting that Obama's endorsement means he "wants four more years of Obama—but nobody else does!" Clinton's account quoted that tweet, replying "Delete your account."
Asked about Trump's tweet, White House Press Secretary Josh Earnest said Obama and Clinton have had some differences, but emphasized the respect Obama gained for Clinton while they worked together.
Obama's endorsement video concluded by turning to Sanders, discussing Sanders' accomplishments in running a campaign many thought would be less competitive than it turned out.
Earnest characterized the Obama-Sanders meeting at his daily press briefing, calling the campaign "a remarkable accomplishment." He said the meeting was friendly, but "focused on the future. Part of that future conversation was about the importance of the upcoming general election."
In the video, Obama thanks Sanders "for shining a spotlight on issues like economic inequality" and bringing young people into the election process. He said the rivals in the election share a hopeful vision for America.
"If we all come together in common effort, I'm convinced we won't just win in November. We'll build on the progress we've made and win a brighter future for this country that we love," Obama says.