Mark Levin is American media's most knowledgeable, passionate proponent of constitutional conservatism. No wonder Chris Matthews hates him. On his MSNBC show this evening, Matthews slurred Levin as "one of the most distasteful human beings out there." Matthews' attack came in the context of commenting on the defense that Levin and Rush Limbaugh have mounted against Donald Trump's claim that Ted Cruz is "nasty." View the video here.