The standard for "obscenity" is defined in the leading Supreme Court case Miller v. California, which held that obscene material was not protected free speech. I won't go through the whole test (Wikipedia explains it well), but it generally says that obscene material has to "appeal to the prurient interest" to an average person in the local community, and it has to have no redeeming social values.
So I wouldn't be worried that the "Ruling Party" deems something obscene or not. Instead, I would be worried about what the "average person" thinks. Isn't that a little odd--that your constitutional rights depend on what your neighbors think?
(That was an argument that one of my law professors made, and I think it's pretty compelling.)