A Democratic mayor from Braddock, Pennsylvania, who is hoping to beat out establishment candidates to be the party's nominee for Senate this year just endorsed Bernie Sanders for president.

John Fetterman, a small-town mayor running for Senate, said in a video posted by his campaign Thursday that he and Sanders are the "most progressive candidates in our respective races" and that he is proud to have Sanders' back in the fight against "the interest of corporations."

"Bernie and I entered our respective races because we believe in the kind of politics that’s about standing up for people instead of catering to corporate influence," said Fetterman. "We represent everyday working people that have otherwise been disenfranchised from the political process by the millionaires and billionaires."

The Fetterman endorsement does not directly call out Hillary Clinton, but he seems to take many shots aimed at her.

"I'll always choose the innovator over the evolver," wrote Fetterman in an email to supporters announcing his campaign. "Bernie's proven that you can run a strong campaign without selling your soul to billionaires."

Fetterman's endorsement video featured him standing beside the famed Wall Street Bull and was posted just hours after the Sanders campaign posted its ad that portrayed Clinton as the financial industry's preferred candidate.

Fetterman said that unlike the other candidates, he and Bernie can't be bought by giant corporations.

"Millionaires and billionaires can go shopping for candidates like it's a trip to the grocery store," said Fetterman. "Giant corporations are buying elections and rigging the system in their favor, and establishment politicians have forgotten where actual people fit into the equation."

Fetterman's endorsement made him the only statewide candidate for office to formally put his support behind Sanders, according to the Philadelphia Inquirer.

Fetterman, like Sanders, is fighting against candidates who the Democratic establishment would prefer to win. Party leader Harry Reid predicted definitively in October that Fetterman's opponent Katie McGinty "is going to win that primary" and said that he wished that she was not being challenged by others in the party.

Reid has openly been working to rally support behind McGinty, who he believes gives the party the best chance to take Pennsylvania's Senate seat back from Republicans in this years election.

McGinty, however, has failed to drum up the same level of enthusiasm that Fetterman has. The support for his campaign convinced the chairman of the Pennsylvania Democratic Party that he would be the "toughest candidate" for Republicans to beat in November.

"I think Fetterman is more competitive than people think he is," said chairman Marcel Groen. "Because he’s so different, and he’s really good on issues. I think he’d be the toughest candidate in the general election. In a society looking for different, he could catch on."

Democratic voters in Pennsylvania will select the party's nominee for both president and the Senate on the same day.

Although Clinton led Sanders by a large margin in the last poll conducted in the state, her national lead over him has rapidly diminished in recent weeks.

Election analysts have predicted since early in Fetterman's campaign that he may be able to ride the wave of support for outsider candidates amongst the American people that has catapulted both Sanders and Donald Trump to prominence.