Reliable Sources panel slams Beck's Obama-"racist" remark: "out of bounds," "stupid," "crazy sells" 

this is not a 1st ammendment issue.
The 1st ammendment only protects free speech against government sanctions. If Beck wants to be a clown it is his right to do so... whether it helps him or hurts him in the long run is up to Fox News and the public perception.

When the Dixie Chicks spoke out aganst President Bush the right was calling them all sorts of names and were rallying against them. It's of the same vein... although the Dixie Chicks weren't politicall commentators.

This isn't a First Amendment issue. The Government isn't trying to prohibit anyone's freedom of speech. A private entity such as CNN can.

"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."

I seem to recall a certain Presidential spokesperson telling television entertainers to watch what they say. Was that before or after 2009?

Beck has said that Obama is both a fascist and a black radical militant. Which is like saying that Glenn Beck is both 30 feet tall and only measures one micron.