US election 2016: Bernie Sanders soldiers on amid calls for party unity

The Vermont Senator announced plans for a rally in Washington DC as his congressional backers acknowledged Hillary Clinton was now the presumptive Democratic nominee

Bernie Sanders addresses supporters in Santa Monica, after a disappointing result in California cut off his final path to the Democratic nomination ((Getty Images))

Hillary Clinton is now the undisputed Democratic nominee for President – but Bernie Sanders is still disputing it all the same. The former Secretary of State swept through the final primary states on Tuesday, picking up convincing wins in New Jersey, New Mexico, South Dakota and California. Mr Sanders has said he will fight on regardless, despite growing calls from his own supporters to quit a race that he has already lost.

The Vermont Senator had staked his campaign on staging one final upset in California, where recent polls had put the two Democratic hopefuls in a dead heat. In the event, Ms Clinton claimed the Golden State by a comfortable 13 points, 56 to 43 per cent. Yet as the stark results rolled in, Mr Sanders nonetheless assured an emotional crowd of his supporters in Santa Monica, near Los Angeles: “The struggle continues.”

The 74-year-old said he intended to “fight hard” to win the final primary in Washington DC on 14 June, and then “take our fight for social, economic, racial and environmental justice” to the Democratic convention in Philadelphia. Mr Sanders has announced he will hold a rally in the nation’s capital on Thursday; in the meantime, at least half of his campaign staff are to be laid off, according to the New York Times.

Senator Jeff Merkley, an Oregon Democrat who was his sole supporter in the US Senate during the primary, indicated that he believes Mr Sanders ought to drop out sooner rather than later, telling the Washington Post: “Once a candidate has won a majority of the pledged delegates and a majority of the popular vote, which Secretary Clinton has now done, we have our nominee. This is the moment when we need to start bringing parts of the party together.”

Ms Clinton has now won a clear majority of pledged delegates, not to mention millions more individual votes than her rival. Mr Sanders has indicated that he still wishes to make his case to the party’s superdelegates, who do not vote until the convention but have overwhelmingly offered their support to Ms Clinton. Converting them now would be implausible, even if he hadn’t spent much of the race slamming the very concept of superdelegates.

Arizona Congressman Raul Grijalva, another Sanders supporter, said that in spite of his defiant rhetoric, the Vermont Senator would quickly come to terms with his defeat. “The reality is unattainable at some point. You deal with that. Bernie is going to deal with this much more rapidly than you think,” Mr Grijalva told the Post. The task thereafter will be to convince his most die-hard supporters to come to terms with that defeat, too.

In her victory speech, Ms Clinton commended Mr Sanders on an “extraordinary” campaign. Insisting that they both agreed on the major issues, she called on his supporters to put aside their resentments ahead of the general election. “It never feels good to put your heart into a cause or a candidate you believe in and to come up short. I know that feeling well,” she said. “But as we look ahead to the battle that awaits, let’s remember all that unites us.”

President Obama, who is expected to endorse Ms Clinton in the coming days, called both Democratic candidates on Tuesday evening, congratulating his former Secretary of State on what the White House said was a “historic” campaign that had “inspired millions and is an extension of her lifelong fight for middle-class families and children.”

At Mr Sanders’s request, he and the President are to meet on Thursday, for what White House press secretary Josh Earnest described as a “conversation about the significant issues at stake in this election,” adding: “The President looks forward to continuing the conversation with Senator Sanders about how to build on the extraordinary work he has done to engage millions of Democratic voters, and to build on that enthusiasm in the weeks and months ahead.”

There were boos in Santa Monica when Mr Sanders mentioned Ms Clinton’s name and, as he celebrated his last few uncontested Republican primary victories at his golf club in Westchester, New York, presumptive GOP nominee Donald Trump invited disaffected Sanders voters to come over to his side. “To all of those Bernie Sanders voters who have been left out in the cold by a rigged system of superdelegates, we welcome you with open arms,” the billionaire said.

But while he refused to concede defeat to Ms Clinton, Mr Sanders reserved his criticism for Donald Trump. “The American people will never support a candidate whose major theme is bigotry,” he said. “We will not allow Donald Trump to become president of the United States."