Bernie Sanders, who saw his once strong lead in the Democratic primary evaporate as the party’s establishment lined swiftly up behind rival Joe Biden, ended his presidential bid on Wednesday, an acknowledgment that the former vice president is too far ahead for him to have any reasonable hope of catching up.

The Vermont senator’s announcement makes Biden the presumptive Democratic nominee to challenge President Donald Trump in November.

Sanders plans to talk to his supporters later on Wednesday.

Sanders initially exceeded sky-high expectations about his ability to recreate the magic of his 2016 presidential bid, and even overcame a heart attack last October on the campaign trail. But he found himself unable to convert unwavering support from progressives into a viable path to the nomination amid “electability” fears fueled by questions about whether his democratic socialist ideology would be palatable to general election voters.

The 78-year-old senator began his latest White House bid facing questions about whether he could win back the supporters who chose him four years ago as an insurgent alternative to the party establishment’s choice, Hillary Clinton. Despite winning 22 states in 2016, there were no guarantees he’d be a major presidential contender this cycle, especially as the race’s oldest candidate.

Sanders, though, used strong polling and solid fundraising — collected almost entirely from small donations made online — to more than quiet early doubters. Like the first time, he attracted widespread support from young voters and was able to make new inroads within the Hispanic community, even as his appeal with African Americans remained small.

'One of the most powerful voices of change'

Democrat Joe Biden, in a post on Twitter said Sanders was a "great leader and one of the most powerful voices for change in our country".

Biden also urged voters backing his former rival Bernie Sanders to join his campaign.

“I see you, I hear you, and I understand the urgency of what it is we have to get done in this country,” Biden said in a statement addressed to Sanders and his supporters. “I hope you will join us. You are more than welcome. You're needed."

In a tweet, President Donald Trump said the race for the nomination of the Democratic presidential candidate had ended "just like the Democrats and the Democratic National Committee wanted" and added that "the Bernie people should come to the Republican party".