With Michael J. Fox the center of attention in the midterms this week, it was only natural that he would do a sitdown interview. Katie Couric — certainly proving how much the evening newscast has changed — devoted more than seven minutes of “The CBS Evening News” to an exclusive interview with Fox, who revealed that, contrary to Rush Limbaugh, he actually was overmedicated when he did ads for Missouri U.S. Senate candidate Claire McCaskill because of her support of stem cell research. Limbaugh later apologized to Fox. When asked what he thought when he heard about Limbaugh’s comments, “My first thought was no, are you kidding me? And then I thought, well, you know I knew there’d be a swift reaction from some reporters and I knew there’d be that celebrity tag, which always kills me because the people who throw that celebrity tag around are themselves such huge celebrities and incredibly well paid celebrities, and you know, really have no more God-given right to have a platform than I do or any American does.” The outcry created by Limbaugh may have turned attention away from McCaskill’s campaign, but it undoubtedly helped raise visibility of the stem cell issue. Opponents of embryonic stem cell research have unleashed their own spots featuring Jim Caviezel and Patricia Heaton, but they don’t have nearly the impact of Fox’s spots, or his appearance with Couric.