Democratic insiders are warning that party voters could cast their 2020 vote for President Donald Trump if Vermont Senator Bernie Sanders wins the Democratic nomination.

They believe that 'the vast majority of Democrats' just 'do not believe in socialism' and would not cast a vote, would vote third party, or even vote for Trump if self-proclaimed socialist Sanders was the Democratic option.

Sanders has led recent polls in Iowa ahead of Monday's caucus and has also shown a strong lead in New Hampshire. Former Vice President Joe Biden maintains his national lead.

Large donors claim many Democrats won't stand with Senator Bernie Sanders if nominated

Democratic insiders claims some Democrats would vote for President Trump over Sanders

Several large Democratic donors are among the voices warning that a Bernie Sanders nomination would spell disaster for Democrats if facing off with Trump in November.

Some have even compared it to the British Labour Party's disastrous election campaign in December 2019 when leader Jeremy Corbyn was annihilated by Conservative Party leader Boris Johnson.

'I'll still put a Bernie Sanders bumper sticker on my car, but a lot of people won't,' Jim Kessler, executive vice president for policy at Democratic think tank Third Way, told the New York Post. The think tank does not align with any one Democratic candidate.

'They'll say "I don't like Donald Trump, but I don't like Sanders either. We survived four years of Trump, maybe we'll survive another four years."

'They'll stay home, vote third party, or vote for Trump,' he added.

Jim Kessler, executive vice president for policy at Democratic think tank Third Way (pictured right) thinks centrists will 'stay home, vote third party, or vote for Trump' over Bernie Sanders

An insider on the Michael Bloomberg campaign also claims his supporters won't back Sanders

An insider on the Michael Bloomberg campaign claims that supporters of centrist candidates such as Bloomberg, former Vice President Joe Biden, and South Bend, Indiana Mayor Pete Buttigieg would be unlikely to stand with Sanders if he beats their chosen candidate.

The former New York mayor is currently polling at just one percent in Iowa and two percent in New Hampshire, according to recent polls.

'I think that there is a very real 'Never Bernie' sentiment amongst both the donor class and moderate, centrist Democrats, or what I would call regular Democrats,' the insider said.

'Bloomberg and Pete [Buttigieg] and [Joe] Biden, who represent the heart and soul of the party — their supporters are not as apt to support someone like Bernie.'

It is believed that suburban and older voters, in particular, would be reluctant to back Bernie with only 32 percent of Baby Boomers showing favorable views of 'socialism', according to a November 2019 Gallup poll.

This compares with 39 percent of Generation X and a 50:50 split among Millennials who favor socialism.

'For Democrats to win, the election must be a referendum on Trump and not a debate about socialism,' said longtime Democratic donor Michael Kempner. He has cut check for eentrists Biden and Buttigieg.

'The vast majority of Democrats and the nation do not believe in socialism.'

According to Politico, such is the concern about a potential Sanders nomination that a small group of Democratic National Committee members have looked to weaken his campaign and head of a brokered convention.

Politico reports that half a dozen members have discussed a policy reversal that would see super delegates, now called automatic delegates, be able to vote on the first ballot at the party's national convention, increasing the influence of DNC members, members of Congress and other top party officials.

For two years after the 2016 convention, which saw Hillary Clinton receive the most super delegate votes and eventually clinch the nomination, the move to relegate the super delegates was a high priority for the DNC.

The policy change was also a massive win for the left after Sanders supporters voiced they frustration at the 2016 automatic delegate voting.

A Bernie Sanders campaign insider said they are aware of the 'Never Bernie' movement

Former DNC chair Donna Brazile claimed that there was no such anti-Bernie movement

'[DNC Chairman] Tom Perez fought tooth and nail to ensure our nominee would be chosen by pledged delegates, not automatic delegates,' David Bergstein, a DNC spokesman, told Politico in an email, arguing that no policy reversal was in play.

'The DNC passed these reforms unanimously. These rules make our party stronger and help ensure our eventual nominee has the full support of the party behind them.'

Former DNC chair Donna Brazile also claimed that there was no such anti-Bernie movement in place.

'There's nothing coming from the DNC, party leaders or those who are in the loop. Donors get moody all the time'' she told The Post.

A person close the Sanders campaign told that Post that they were aware of the 'Never Bernie' movement but there was 'no point in being afraid of it'.

The first vote on the Democratic candidates will take place this Monday, February 3, in the Iowa caucus.