The Demise of Crossfire

I can see no reason whatsoever to be upset at the demise of Crossfire and especially with CNN cutting all ties to Tucker Carlson. What's amazing to me is the role Jon Stewart played in the show being cancelled.

When was the last time a comedian had such power in America? I guess Dick Gregory who played a major role in the Civil Rights movement. But I can't think of another comedian who comes close to Stewart in this sense.