Naturally, when someone comes forward with evidence that they have access to large stocks of pills and are selling them to anyone who knows them well enough to ask, your next course of action is to focus all of your time and energy on just one person that they sold to. Why cut off the snake's head when it's so much fun watching that tail grow back every time, you know? So, with their priorities appropriately out of order, Wilma Cline was given immunity, and authorities launched a three-year investigation that culminated in ... Rush Limbaugh having all charges dropped in exchange for going to rehab.
Way to keep us safe, law enforcement community of Florida!
Why It Should Have Destroyed Him
Prior to 2003, the war on drugs and its various casualties were a target that Rush Limbaugh set his sights on regularly. He built his career on lecturing those who lived outside his rigid moral code. This drug scandal was a fundamental breach of the informal contract Rush Limbaugh had with his audience. His days as a morally superior blowhard should have come to an end the moment he had to go on the air and admit to his legions of rabid fans that he was a drug-using, law-breaking criminal, just like those people he spoke out against so vehemently. Relatively speaking, it's kind of like the guy who speaks out against gay marriage and eventually gets caught in an airport bathroom stall blowing some random dude. You just can't trust his gay hate for a single second after that, right? Right. That was a fantastic analogy.
Just doing my job, folks.
Why It Didn't
Rush Limbaugh survived his drug scandal because the people who listen to him are not doing so because they're seeking the truth. People turn to Rush Limbaugh when they need a mouthpiece for all of the sexist/racist/homophobic thoughts that they wouldn't dare give voice to while in the company of friends or colleagues. In a time when calling every woman you see "sweetheart" and assuming that every person of color is "the help" is frowned upon, listening to Rush Limbaugh is like a secret confirmation that you've planted your flag firmly on the side of the bigot. It might not be popular to tell people that anymore, but listening to someone who at least pretends to feel that way too is still all the rage in some circles. We have entire television news networks dedicated to it these days.
Rush Limbaugh knows better than anyone that telling people they aren't assholes for being total assholes is a service that's scandal-proof.