We learned a few other things about the Democratic presidential hopeful when he was later put on the "hot seat" by the hostess, earning $1,000 for charity for every question he answered honestly.
Sanders wears briefs, not boxers. He's been in handcuffs -- for "a civil rights demonstration" during his youth, he quickly clarified. When he was growing up, he wanted to be a social worker. And the one song he would perform if doing karaoke .... well, you know, it's that one from Saturday Night Fever.
"I can't remember the name of the song," Sanders said, offering that it was "the one with John Travolta walking the street.
"Stayin' Alive?" Yes!
By the time the segment ended a few minutes later, the show's producers had located a clip of the Bee Gees classic and Sanders did his best to groove and clap some more.
Dancing with Ellen may soon be a rite of passage for presidential candidates. Last month, Hillary Rodham Clinton appeared on the show and spiced up a commercial break by performing the popular dance move to Silento's "Watch Me (Whip/Nae Nae)."
Clinton was also referenced during Wednesday's taping. DeGeneres recounted that Tuesday night's Democratic debate was held in Las Vegas and showed doctored images of Clinton taking stage as a scantily clad show girl.
There was also talk about Sanders's performance during the debate, particularly the moment when he told Clinton that “the American people are sick and tired of talking about your damn e-mail."
DeGeneres praised Sanders for avoiding attacks on his rivals. Sanders also got a chance to talk about his biggest cause on the campaign trail: income inequality. And DeGeneres poked fun at Sanders's often unruly white hair, showing the audience some blown up pictures of some particularly bad moments.
The syndicated show airs Thursday.