The First Amendment
Americans seem to be confused about the First Amendment.
One part of the First Amendment prohibits the government from infringing on speech.
Don Imus has not been fired by the government. He was fired by a corporate entity that made the decision that Imus’ description of the Rutgers basketball team had made him a commercial liability.
The Dixie Chicks claimed that their First Amendment rights were violated when people stopped buying their records.
You have the right to say (almost) whatever you want in America. The government won’t stop you. But customers have the right to stop patronizing you if you say things they don’t like. The fact that people take their business elsewhere does not a First Amendment violation make.