The Democratic dark horse is starting to make Hillary Clinton supporters sweat as he grows in popularity. Who would have guessed that Bernie Sanders would get a lot of celebrity love. He's polling second for the Democratic presidential nomination and is trailing only TKTK points behind Clinton. And as Clinton attempts to drum up support from the Hollywood elite, many of them are starting to turn to Camp Bernie, including one very green supporter — the Hulk himself.

Okay, so maybe "The Hulk" isn't actually endorsing the Vermont socialist, but actor Mark Ruffalo, who portrays the big man in the Avengers franchise, has been extremely vocal about his support for the senator. Though initially an Elizabeth Warren fan, Ruffalo has nothing but praise for Sanders. "I think Sanders has a message," Ruffalo told The Daily Beast. "Hillary’s going to have to adopt Bernie’s message, and I think we’re going to be hearing a lot more from Bernie."

Ruffalo went on to discuss his admiration for Sanders' commitment to discussing wealth inequality within the country. Due to his critical views on the 1 percent, as well as the fact that he is one of the only non-millionaires running in the election, Bernie is an unexpected candidate whose message would resonate with wealthy celebrities.

But Ruffalo isn't the only one jumping on board with the far left politician. Sanders' campaign launch rally featured several surprise celebrity guests, while even more have taken to social media to voice their support.

Neil Young

The folk music icon was one of the first celebrities to publicly announce his support for Sanders and made headlines when he called out Republican candidate Donald Trump. During Trump's campaign announcement, Trump used Young's hit song "Rockin' In The Free World" without the singer's permission. Young did not appreciate it and released a statement via his manager stating, "Donald Trump's use of "Rockin' in the Free World" was not authorized. Mr. Young is a longtime supporter of Bernie Sanders."

Ben & Jerry

That's right. The ice cream gods have blessed a possible Sanders presidency and made an appearance at Sanders' campaign kickoff in Burlington, Vermont, the same town where Ben Cohen and Jerry Greenfield launched their ice cream empire. The two introduced Sanders, and provided free ice cream to those who attended. We can only hope that they create a special Sanders-inspired ice cream

Sarah Silverman

The actress/writer/comedian/personality expressed her support for the candidate on Twitter, citing her approval of the fact that he is "not for sale." Sanders has been vocal about his grassroots support base and that the overwhelming majority of his campaign funds have been donated by individual citizens, rather than corporations.

Susan Sarandon

Like Silverman, Sarandon made her unofficial endorsement on Twitter when she shared a video of Sanders' speaking out in opposition of the Iraq War. Sanders supporters frequently cite Sanders' anti-war stance when comparing him to other Democratic candidates, such as Clinton, who voted in favor of the war.

Lewis Black

Black was apparently very excited when Sanders announced his candidacy because he finally had a fellow socialist to endorse. “I’ve said from the beginning that I’m a socialist, and now I have a candidate running," the comedian told The Daily Beast. "We have no party. There’s like seven of us. I’ve got no meetings to go to. So I’m excited."

Julian Casablancas

In addition to being unexpectedly dreamy, The Strokes singer Julian Casablancas is also getting political after he took to Twitter to throw some love in Sanders' direction in late May. Like Sarandon, he shared his opinion that Sanders is "the only candidate not being bribed."