> It appears that CBS sees equal airtime as a very serious threat to their programming.

This seems very dubious given the recent ownership change of CBS and the lack of reason behind the decision. The point the parent comment brings up is that "equal airtime" requires that someone actually request to go on the show and be refused. There is no legitimate cover for CBS' decision as this did not occur. It seems incredibly likely to be one made in fear of political liability rather than legal.