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.

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.

Late-night hosts took a moment out of their shows Monday night to share their thoughts about CBS cancelling The Late Show with Stephen Colbert — and they didn't hold back.