Stephen Colbert says he won't sell out to Mike Bloomberg. Not for free, anyway.

This never-ending season of America's Next Top Democrat just keeps running, and taking the catwalk this week was Joe Biden.

Biden spun a tale of being arrested while attempting to visit Nelson Mandela in prison, a compelling story that would be much more compelling were it true. As Late Show host Stephen Colbert points out, the presidential candidate was merely separated from his party at the airport — though the event seems to have stuck with him in the decades since.

"Nelson Mandela was in prison for 27 years, but one time I lost sight of my coworkers in the Delta terminal so I get it," said Colbert, impersonating Biden.

Biden isn't the only Democrat whose campaign is resorting to some questionable tactics, either. Mike Bloomberg's presidential campaign has hired a former television executive to get his campaign points into late night show monologues — including Colbert's. And unlike his expensive carpet-bombing of just about every other aspect of the media landscape, Bloomberg doesn't want to pay for it either.

"As a principled comedian, I would never shape my content around a person or a brand for free," Colbert declared. "That would be a betrayal of all the brands who pay me."