This is an excellent article and it'll come as no shock to hear that I'm not a fan of Derrida or post-structuralism in general. Relativism is a very dangerous way for a society to function and needs to be pointed out as problematic wherever it's found.

With regards to language and reality - there's some interesting reading around Sapir-Whorf, but I'm not entirely sure where I sit on this ongoing debate yet. I'll do more reading and get back to you.... having said that, it's a world away from the sort of political relativism you're rightly highlighting. Great article, very informed and enjoyable.