Former 2020 Democratic presidential candidate Andrew Yang endorsed former Vice President Joe Biden Tuesday night and called for Democrats to unite behind Biden ahead of the general election.

Yang, now a CNN contributor, made his endorsement on live TV as the results from six more primary contests showed Biden widening his delegate lead over Sen. Bernie Sanders of Vermont.

"I believe that Joe Biden will be the Democratic nominee, and I've always said I'm going to support whoever the nominee is. So I hereby am endorsing Joe Biden to be not just the nominee for the Democratic Party, but the next president of the United States," Yang declared.

Yang, who supported Sanders in 2016, called the self-described democratic socialist "an inspiration," but said the delegate math made it clear that he was not going to win the Democratic presidential primary race. And he said it was time for Democrats to focus on their main objective.

"We need to bring the party together. We need to start working on defeating Donald Trump in the fall," Yang said.

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An entrepreneur who rose from political obscurity last year, Yang outlasted sitting Democratic governors and senators in the crowded presidential field before exiting the race in February. Yang's principal issue in the campaign was the steady loss of jobs to automation. His proposed solution was a universal monthly income of $1,000 for all Americans.

That signature issue, combined with an easygoing, laid back demeanor helped the political novice win the loyalty of devoted supporters who referred to themselves as the Yang Gang and who advocated passionately for the candidate on social media.

But after failing to win any delegates in the Iowa caucuses or New Hampshire primary, Yang ended his campaign. The candidate whose main slogan was "MATH" – an acronym for "Make America Think Harder" – told his supporters that the numbers simply did not show that he had a path to victory.

Ahead of the Iowa caucuses, Yang told Bloomberg News that his supporters and Sanders supporters "have a lot of overlap." He said Biden called him last week seeking his endorsement but he declined because he "has such admiration and respect for Bernie."

"I think Bernie has called out the real problems in a very powerful and necessary way," Yang said. "So, I wanted to let the Democratic process play out and I believe it has. At this point, you can see very clearly that Biden is building a delegate lead that is only going to grow in the days ahead."

"So, we need to come together as a party, starting tonight."

When asked what he would tell Sanders supporters who may be hesitant to rally behind Biden, Yang said, "I get it."

"I get the frustration. I get the desire for a revolution. I get the fact that it seems like our institutions are failing us right and left. I get all of that. It's why I ran," he said. "But we have to defeat Donald Trump in order to make progress on the climate, on any of these problems in a bigger way,"

Contributing: Jason Lalljee and Rebecca Morin