2020 election: Joe Biden could lose to Trump if he fails to win over Bernie Sanders supporters, campaign adviser warns

Key policy differences are keeping Bernie supporters from backing Biden

Joe Biden's failure to inspire Bernie Sanders supporters could lead to his defeat by Donald Trump in November, a senior adviser to the Bernie campaign has warned.

In a blog post published to Medium on Friday, the "America's Promise PAC" said there is a "clear and dangerous trend" that could keep the Democrats from the White House.

America's Promise was launched by Jeff Weaver, Mr Sanders's former campaign manager. He said a significant portion of Bernie Sanders supporters were "currently unsupportive and unenthusiastic" about the Biden candidacy.

"If all of Sanders' base turned out for Joe Biden in November, he could defeat Trump and take back the White House for Democrats. Here's the problem: significant portions don't currently plan to," Mr Weaver wrote.

In the blog post In 2020, the Path to Victory Runs Through Bernie's, Mr Weaver points to recent polls showing more than one in five supporters of Mr Sanders don't plan to vote for Mr Biden, while six out of 10 say they are "not very excited" or "not excited at all" about Mr Biden's nomination.

A Pew Research Centre poll, meanwhile, showed that 47 per cent of Mr Sanders' supporters wouldn't back Biden over key differences in their policy positions.

"There is a real and urgent need to help Biden consolidate Sanders supporters," Weaver wrote.

"Treating Sanders supporters as throw-away votes will ultimately be at the expense of the party, down-ballot candidates, and our ability to enact real policy solutions for Americans."

"Despite best intentions, the Biden campaign and the DNC are far behind on digital organising, Latino outreach and progressive coalition building."