I think you and Chuck and others who take offense at Dunham and don't find him funny because of "racism" need to unwad your panties.
I'm going to avoid the protracted argument as I'm going to quickly devolve into just yelling and insulting (it's why I can't go into any political thread, as much as I want to tell every single liberal how wrong they are)..
And you were head of your school debate team? Damn. Wish I'd come up against you lot.
The issue with 'edgy' comedy, the way I see it, is how many lines you cross and how inventively you do it. Cross the line once, and you're spewing over-the-top racist propaganda. Go beyond that and cross it twice, and you're in the happy fantasy world of sublime absurdity.
The problem is that with many of these things, Poe's Law can hit you
hard. When legitimate racist propaganda is as absurd as it has often been, it is difficult to differentiate spoof from reality. Just look at the whole LGBT business - how can you parody those prejudiced against homosexuality when the Westboro Baptist Church is playing your whole act straight (pun not intended)? I mean, I'm not saying it's impossible, but you have to be very good indeed to get it right, and Sturgeon's Law dictates that few are.
That's why people often don't find it funny - because they've too often seen very similar stuff delivered with an earnest 'See? That's how they really
are!'.
... Well, that and sometimes it's just not very good, regardless of content.