Marianne Williamson has called former Vice President Joe Biden’s Super Tuesday win a Democrat “coup” after he won nine of the 14 states.

The spiritual guru and book author once had a podium on the Democratic debate stage to vie for her own opportunity to become president, but she dropped out earlier this year after failing to compete with the frontrunners.

In a now-deleted tweet, Ms Williamson, who has since put her support behind Bernie Sanders, expressed outrage over Mr Biden performing so well across America.

“Jake Tapper referred to the ‘resurrection’ of Joe Biden’s campaign,” she wrote, referencing the CNN anchor.

“This was not a resurrection; it was a coup. Russiagate was not a coup. Mueller was not a coup. Impeachment was not a coup. What happened yesterday was a coup. And we will push back,” she added.

Her tweet was later deleted.

Going into Super Tuesday, Mr Sanders was leading in the polls and expected to have an outstanding night with many predicting he would take the majority of delegates in states like Texas.

But voters witnessed a huge rally behind Mr Biden in the last couple days, all of which started when the former vice president won the South Carolina primary.

His win encouraged Pete Buttigieg and Amy Klobuchar to both drop out of the race and endorse the moderate frontrunner. The endorsement of Representative Jim Clyburn of South Carolina also helped give Mr Biden a last minute boost before voters cast their ballot on Super Tuesday.

Marianne Williamson, who now supports Bernie Sanders, called Joe Biden's surge on Super Tuesday a Democratic "coup" (AP)

Frustrated Mr Sanders’ supporters have lashed out at the Democratic Party for what they believe is an attempt to stop the Vermont senator from taking the nomination.

Votes are still coming in from states like California and Maine, but Mr Biden looks to be the new frontrunner in the race for the Democratic nomination. Nine of the 14 voting states were confirmed for Mr Biden on Wednesday morning, and he still has a chance to pick up Maine.