The late-night legend took aim at his former network home and David Ellison's media company, speculating that Colbert's show was canceled for political reasons.

Comedian David Letterman on Friday joined the chorus of late-night hosts to bash CBS News after it announced it would sunset “The Late Show” after more than three decades on air, while praising host Stephen Colbert as a “martyr.

David Letterman delivered a fiery rant against CBS and parent company Paramount for cancelling Stephen Colbert’s “Late Show,” calling the decision “gutless” and “pure cowardice” as he labeled his successor a martyr of the network.