Why did Lou Dobbs "REALLY" leave CNN?

As most of you know Lou Dobbs has left CNN. He announced the departure last night on his show, which was his last on the network. He's what Dobbs said last night:

“Over the past six months, it’s become increasingly clear that strong winds of change have begun buffeting this country and affecting all of us,” Dobbs said. “And some leaders in media, politics and business have been urging me to go beyond my role here at CNN and to engage in constructive problem-solving, as well as to contribute positively to a better understanding of the great issues of our day. And to continue to do so in the most honest and direct language possible.”

My conclusion on why Dobbs left the network was in my opinion due to outside pressure from groups like the ACLU, Hispanic groups like La Raza, liberal groups who has called on the network to get rid of Dobbs for making statements like for example questioning the President's Citizenship status, which made Dobbs look like a fool. But despite all of that, he was my favorite anchors on television. John King, host of State of the Union will replace Dobbs in that time slot in 2010, according to Politico.com.

I expect Fox News to go hard after Dobbs to add to their controversial, but powerful lineup of news anchors on the big network, or he could go over to the fledging Fox Business Ntwork & give that network its flagship anchor.