"Clearly, I favor her opponent," Sanders told CNN in an interview over the weekend. "His views are much closer to mine than as to Wasserman Schultz's."
Sanders told CNN that he wouldn't support Wasserman Schultz leading the Democratic Party if he is elected president.
On Sunday, Sanders sent out a fundraising email for Canova, the fourth congressional candidate backing him to receive his endorsement.
"Like Senator Sanders, I'm running a campaign that's truly backed by the people, not big corporations -- one that stands up to Wall Street interests instead of cozying up to them. Together, I feel confident that our campaign of nurses, teachers, students, seniors and working class Floridians can work together to demand accountability from our leaders, and offer a more positive path forward to the people of Florida's 23rd district," Canova said in a statement.
In a statement, Wasserman Schultz downplayed Sanders' endorsement of her opponent.
"I am so proud to serve the people of Florida's 23rd district and I am confident that they know that I am an effective fighter and advocate on their behalf in Congress," she said in the statement. "Even though Senator Sanders has endorsed my opponent I remain, as I have been from the beginning, neutral in the Presidential Democratic primary. I look forward to working together with him for Democratic victories in the fall."
Wasserman Schultz, who has been criticized by progressives for her stewardship of the Democratic primary, is still favored to keep her seat, and has the support of party heavyweights in her reelection bid -- including President Obama, who endorsed her campaign in March.
According to her most recent campaign finance disclosure, Wasserman Schultz -- who has never had a primary opponent -- raised about $1.5 million since January 2015 and reported $840,000 on hand in through March. Canova, a first-time candidate, reported about $460,000 on hand through March.
Sanders' fundraising boost could help Canova mount a more competitive campaign. According to one source close to the campaign, Sanders' fundraising appeal for progressive House candidates Zephyr Teachout of New York, Lucy Flores of Nevada, and Pramila Jayapal of Washington, raised several hundred thousand dollars for the candidates.
Flores has raised nearly $600,000 since April 1st, with most of that coming after Sanders' fundraising appeal.