It’s not quite clear why he quit.  CNN Foreign Correspondent/Anchor  Jim Clancy came out in the open last week as a self admitted hater of Israel.  After admitting to something, which is generally evident amid all of his colleagues, and quite a popular/common sentiment amid the entire network, he quit.  Why? 

(Via Washington Free Beacon) Longtime CNN anchor Jim Clancy resigned from the network on Friday, just days after engaging in an anti-Israel tirade on Twitter and then deleting his account altogether.
Clancy, a 34-year veteran of CNN, announced his resignation in a note to colleagues that was subsequently obtained by Ad Week.

After nearly 34 years with Cable News Network, the time has come to say Farewell!
It has been my honor to work alongside all of you for all of these years. This is one of the greatest news organizations in the world. It has truly revolutionized information delivery while driving technological advances in how we gather the news.

Through it all, CNN has been a family to my own family. That means something.
As I reflect on all of the great adventures and achievements of the past, I wish you great success in the future.”

Clancy, long accused of having an anti-Israel bias, attacked pro-Israel activists on Twitter in the wake of the attack on French satirical magazine Charlie Hebdo.  Clancy angrily accused several Twitter users of engaging in “hasbara,” or positive PR, for Israel.
“You and the Hasbara team need to pick on some cripple on the edge of the herd,” he tweeted during the meltdown.  (read more)