Groan. Look: as Dan notes, some things just cannot be ignored. When a brutal homophobe sounds and looks like a parody of a big old queen, suppressing that fact becomes close to impossible. I stand by the Corky St Clair comparison. And Corky, remember, self-described as straight. We just never saw his wife (for whom he did most of the personal shopping).
By all means, poke fun. My argument is that ultimately, this kind of joke backfires outside of the community. The comparison that comes to mind is Dave Chappelle's abandonment of his hilarious Comedy Central show when he began to suspect that not everyone was laughing at the same jokes for the same reason:
One particular sketch still disturbs Dave today. The skit was about a pixie (played by Dave) who appeared in black face, which Dave describes as the "visual personification of the n-word."
"There was a good-spirited intention behind it," Dave says. "So then when I'm on the set, and we're finally taping the sketch, somebody on the set [who] was white laughed in such a way—I know the difference of people laughing with me and people laughing at me—and it was the first time I had ever gotten a laugh that I was uncomfortable with. Not just uncomfortable, but like, should I fire this person?"
After this incident, Dave began thinking about the message he was sending to millions of viewers. Dave says some people understood exactly what he was trying to say with his racially charged comedy...while others got the wrong idea.
The issue here wasn't so much that Chappelle was worried his comedy was "offensive" in some generic sense, good comedy often is. It was more that he started to suspect that it was counterproductive, and I think that's the question to ask here. Chappelle made a decision because he worried frat boys were laughing at black people and not the actual jokes. What happens when the folks laughing at Bachmann aren't laughing because he's a homophobe but because "fruits" are funny?