Student or Learner
"None of this implies that the politics of postmodernism are nothing but placeholders for a political desire which dare not speak its name"
What means the underlined part? which kind of political desire is this?
First of all, this type of writing is not what I would recommend for a person trying to learn English. That aside, the phrase "dare not speak its name" is from a poem by Lord Alfred Douglas (1896) The love that dare not speak its name where "The love that dare not speak its name," was homosexuality.
In your example, without more context, I can only assume that by the "political desire which dare not speak its name" the author is referring to a dark, embarassing motive such as greed.