(CNN)Stephen Colbert featured a mystery guest on CBS' "The Late Show" Thursday: Sen. Bernie Sanders.
The Vermont senator appeared during the program's "Wheel of News" segment, a parody of "Wheel of Fortune." When the wheel landed on "mystery guest," Sanders' silhouette, surrounded by fog, was revealed from behind a curtain.
Although his appearance was brief, Sanders took the couple of minutes to stress that he was "the strongest Democratic candidate."
His comments followed Colbert's questioning the candidate's belief that, when he starts winning more states, party superdelegates will begin to favor him instead of former Secretary of State Hillary Clinton.
Sanders reminded Colbert that his campaign has won six of the last seven caucuses. "I think that superdelegates should listen to the will of their people," Sanders said. "If you've got 60, 70, 80% of the vote in a state, you know what? I think superdelegates should vote for us."
Colbert joked that the Republican Party probably wishes it had superdelegates to bring a sense of control over their primary process as talks about a contested convention continue to mount.
"Well, that may be," Sanders said. "But I think what we need in the Democratic party is some democracy, and that means that I think when we are defeating Donald Trump in the last polls by 15 or 20 points and when we are the strongest candidate, I believe, in taking on any Republican candidate, I would hope that superdelegates take a look at who the strongest Democratic candidate is and you know what? That's me."
Sanders' interview ended with him spinning "that damn wheel." Sanders acted surprise to see that a man was under the host's desk holding the Wheel of News lever. "What kind of operation are you running here, Stephen?" quipped Sanders.
"It's called a talk show, Bernie," Colbert replied.
Sanders pulled the fake lever to reveal "T-Shirt Cannon," which the White House hopeful embraced, firing two shirts into the audience of the Ed Sullivan Theater.