But are top executives for a major U.S. corporation so sensitive to personal criticism that they're willing to ditch their most popular commentator for saying some bad things about them? That's hard to believe.

Another hypothesis is that Carlson was also saying bad things about Fox News colleagues. That too doesn't make much sense to me. Doesn't that sort of thing go on in most large companies? It's called human nature. Again, it doesn't seem serious enough to can the network's most popular commentator. 

Let me weigh in on another possibility — that the Pentagon and the CIA may have been the ones who put the quietus on Tucker and possibly signaled to Fox executives that he had to go.

Last December, Carlson broadcast a program on the assassination of President Kennedy in which he accused the CIA of having participated in the assassination. In doing so, Carlson violated a taboo that has existed within the mainstream media since November 22, 1963, the day that Kennedy was assassinated. 

It's considered permissible for the mainstream press to run articles and programs that analyze the assassination in an "objective" way, or that support the official lone-nut narrative, or that analyze why people subscribe to conspiracy theories. But what has been verboten since the assassination is the running of articles and programs that point to the Pentagon and the CIA as the orchestrators of the assassination or that feature evidence pointing to their criminal culpability.