Two years after a little-known college professor pulled off a stunning upset by defeating the House majority leader, Eric Cantor, in a Republican primary contest, another obscure professor is hoping to replicate that feat in Florida, riding a wave of progressive fervor that seeks to upend the Democratic Party’s leadership.

Senator Bernie Sanders of Vermont, frustrated by how he has been treated by Democratic Party officials in his primary campaign against Hillary Clinton, bolstered that effort over the weekend when he endorsed Tim Canova, a law professor at Nova Southeastern University. Mr. Canova is hoping to unseat Representative Debbie Wasserman Schultz of Florida, the chairwoman of the Democratic National Committee, in a primary contest in August.

The support of Mr. Sanders led to an infusion of more than $250,000 into Mr. Canova’s campaign in less than two days, arming him for a more vigorous fight against the veteran congresswoman.

“She’s certainly out of touch with the grass-roots of the Democratic Party,” Mr. Canova, 56, said of Ms. Wasserman Schultz in an interview. “She has been a very out-of-touch political insider and she has not been representing her constituents well.”