Recent polls also show Biden leading President Donald Trump by at least 5 points in hypothetical head-to-head matchups.
"The absurdity and cruelty of our employer-based, private health insurance system should now be apparent to all," the senator from Vermont wrote.
"Make a $7 contribution to the Democratic Unity Fund today to show your commitment to party unity by helping elect Democrats nationwide," Sanders said in an email to supporters on Friday.
As the Democratic party rallies behind its least inspiring candidate, it's worth taking stock what America and the world lost out on in these primaries. One thing is certain—Biden won't solve the issues that produced the Trump presidency.
Both Obama's endorsement of Biden and Clinton included a call for unity and praise for Bernie Sanders, the Vermont senator who failed to clinch the nomination in both primary contests.
"This is not just about Donald Trump," she said. "It's about a systemic structure in this country that is set up to fail working-class people, the young and people of color. We need a real plan and not just gestures."
"With the utmost respect for Bernie Sanders, who is an incredible human being & a genuine inspiration, I don't endorse Joe Biden," Gray tweeted Monday.
"President Trump's supporters will run through a brick wall to vote for him. Nobody is running through a brick wall for Joe Biden," the president's campaign manager said.
Trump narrowly beat Hillary Clinton in several battleground states that Obama had won in 2008 and 2012. Democrats aim to win back these states in 2020.
In his first major interview since suspending his presidential campaign, Vermont Senator Bernie Sanders said he hoped to work with former Vice President Joe Biden and "move him in a more progressive direction."
Did Sanders' campaign fail or succeed? Expanded health care, a higher minimum wage, free college: His ideas may have outgrown the need for Sanders himself and his purist approach.
Sanders said on Wednesday that Joe Biden is "going to have to bring new people into his political world" in order to win over Sanders' supporters.
"Joe Biden has the humanity, empathy and steadiness we need in a leader," The Lincoln Project said Wednesday.
"Sanders never wanted to win, like so many ideologues, he wanted to lose. It makes him feel virtuous," the Fox News host said.
"The COVID-19 epidemic highlights the folly of tying health coverage to jobs," a co-author of the analysis told Newsweek.
Recent poll results show Biden holding leads over Trump in both national and statewide polling in key states.
Democratic voters across the country largely rejected the candidates pushing for universal health care in the primary race.
Without Senator Bernie Sanders, the 2020 presidential election will be a race between former Vice President Joe Biden and President Donald Trump.
The delegate math eventually became stacked against Sanders in 2016, and that is now the case for him in 2020.
"Today I am suspending my campaign. But while the campaign ends, the struggle for justice continues on," Sanders tweeted.
"We are listening to our people and, you know, we've got to make the best decision that we can," the progressive senator from Vermont said.
The majority of Florida voters also said they disapprove of Trump's handling of the coronavirus pandemic.
The comedian and Bernie Sanders doppelgänger said that the Vermont senator "should drop out" of the 2020 presidential race, telling a New York Times columnist over the weekend that "everybody" should support former Vice President Joe Biden's campaign.
The Democratic presidential candidate commented that it's easier for status quo forces to maintain a broken system than to fix it.
"We urge you to fully commit to eliminating all patient cost-sharing for COVID-19," the groups wrote in an open letter.
Progressive lawmakers, including presidential candidate Bernie Sanders, have argued that the crisis shows a universal health care system is needed.
"What we're not talking about right now, Seth, is that if you're making 14 bucks an hour, 12 bucks an hour and that check stops coming in, which is the case, how are you going to feed your family? How are you going to pay the rent?" Bernie Sanders said during a Monday appearance.
A poll by Harvard and Harris conducted from March 24 to 26 shows Biden beating Trump by 10 points, 55 percent to 45 percent.