How does Fluther keep the raving, Teabagging lunatics away?

Just about every other Q&A site I’ve visited seems to be dominated by maniacal, single-minded US Republican Party supporters posting a non-stop stream of racist, sexist, homophobic, anti-health care, anti-Obama propaganda posed as pejorative questions. Their sheer dogged determination and relentlessly aggressive stupidity eventually drives enough people away that they become the majority. (See Y!A politics section, for an example of what I’m talking about.) I’m curious how Fluther has managed to avoid this fate (thus far). I’ve seen only a tiny handful of “ZOMG BIRTH CERTIFICATE!!!!!!” type questions posted here, and I’d really be interested to know why, when it’s so nearly universal everywhere else.