David M Jackson

USA TODAY

Fox News sought Sunday to enlist a high-profile supporter for its campaign to land a Democratic presidential debate: Democratic presidential candidate Bernie Sanders.

The Vermont senator sounded somewhat equivocal during his appearance on Fox News Sunday. "If I could have a guarantee -- and knew who the questioners were, and if the framework for the debate was fair -- I would have no objection," Sanders said.

Fox News Sunday host Chris Wallace had asked Sanders: "The Republicans have held debates on all the networks. But the Democrats so far have refused to hold a debate on Fox ... Would you be willing to participate in a Democratic debate on Fox News?"

(Wallace also noted that other Democratic candidate, Hillary Clinton, has declined to appear on Fox News Sunday during this election cycle.)

Many Democrats criticize Fox News for what they call its conservative slant. Fox officials say their network is in fact "fair and balanced," and cite their tough questioning of Republican candidates during the GOP debates it has sponsored.