To quote Max Plank, "that's not even wrong."
I see what's going on here. You're exhibiting cognitive dissonance. You know you should support Free Speech. After all, every freedom-loving person supports Free Speech, right? But there's conflict. You know that the law allows for speech that you disapprove of. So you need to engage in what psychologists call "dissonance reduction" in order to reconcile your "ideal" of Free Speech with your desire to restrict speech. Your dissonance reduction of choice is to deny information that conflicts with your preexisting beliefs. In this case, you deny that the Free Speech protections found in Watts v. United States are truly the law of the land. Therefore, when you advocate eliminating those protections, you're not really in opposition with Free Speech.
Compare your dissonance reduction with a person who wants a healthier diet and to limit high fat foods. He starts eating a doughnut. He knows that eating a doughnut is not a healthy choice, and this creates cognitive dissonance. So he simply denies that the doughnut is a high fat food. Presto! Cognitive dissonance reduced. Watts v. United States doesn't protect crude, offensive political hyperbole. Presto! Cognitive dissonance reduced!