Below is my list of ideas about which it is impermissible to speak in polite society in the US in 2013. Can you add to it?
"The number and range of ideas about which I may not speak or write and still hope to be employed or loved is large and various, and it is continually expanding. In the United States, such ideas include a belief in innate racial differences; the superiority of men at any mental activity; the inalienable rights of corporations and the State; the efficacy of violent resistance; and the justice of the Confederacy’s cause or of the Jewish state. In polite society, I may not deny the anthropogenic causes of climate change, nor the HIV cause of AIDS, nor the historical events of the Holocaust. More generally, it is unacceptable to speak or write about many ordinary events in human life, including abortions, or diseases (particularly, genetic disorders), or depression, or how our loved ones actually die. Without specifying, I have believed a few of these ideas, harbored my doubts, and experienced most of those events, but I cannot be candid."
I may remove the list of "denialist" beliefs, because none of them are beliefs that a reasonable person of good conscience could believe. All three denialisms are contradicted by the facts.