I don't think it would be a big deal at all if Limbaugh would, from time to time, show a sense of self-irony and portion of humor.
Right now, Limbaugh is known for bashing everyone left and right, drug addicts have been a fave target of his in the past.
Then we find out he's an addict himself.
He repeatedly takes shots at Democrats and also wrongly labels them as "Libs", BTW.
It's like no matter what a Democrat says, Limbaugh will blast it.
Someone who doesn't listen and just plays a pre-rehearsed message, the way Limbaugh does, isn't interesting.
There are tons of Republicans, and Democrats, that don't just put on the auto-pilot message the way Limbaugh does.
Limbaugh loses credibility, even among Republicans (I doubt that he's lately been able to swing any voters TO the Republicans, rather AGAINST) and only the truest worshippers are soon going to tune in when he speaks.
The comment isn't that big deal in itself.
What matters is that it comes from Limbaugh. A man who never makes fun of himself, or ridicules right-wingers.
Had Limbaugh frequently made jokes about his fatness, or about his drug addiction, or similar stuff, then my guess is that he would've got away with it.
-Hedge