Before Fox News, Tucker Carlson worked at CNN. The show he co-hosted was canceled after a tense on-air exchange where Jon Stewart called him a 'dick.'

• Tucker Carlson worked at CNN before he helmed the top-rated show at Fox News. 
• Jon Stewart once called Carlson a "dick" on the show Carlson hosted on CNN, "Crossfire."
• The tense 2004 exchange went viral, and the show was canceled months later. 

Long before Tucker Carlson hosted and then was fired from Fox News' most-watched primetime cable news show, he worked at CNN. 

The far-right firebrand media personality co-hosted CNN's now-defunct "Crossfire" show beginning in 2001. The political debate-styled program was canceled in 2004 after a tense on-air exchange where comedian Jon Stewart called Carlson a "dick."