Specifically, Arizona Governor Jan Brewer signed a law making the teaching ethnic studies illegal. From the Times:
"Under the law signed on Tuesday, any school district that offers classes designed primarily for students of particular ethnic groups, advocate ethnic solidarity or promote resentment of a race or a class of people would risk losing 10 percent of its state financing.
'Governor Brewer signed the bill because she believes, and the legislation states, that public school students should be taught to treat and value each other as individuals and not be taught to resent or hate other races or classes of people,' Paul Senseman, a spokesman for the governor, said in a statement on Thursday."
Generally, I have somewhat conflicting thoughts on ethnic/women's/LGBT/race studies. On the one hand, ghettoizing these Other Studies' courses into their own classes can reinforce the conception that the histories of Others is not Real History, and is less important than other historical narratives. However, because the historical narratives from the perspective of Others are rarely prioritized or centered in Real History courses and texts, Other History courses are still needed so people will be exposed to history about folks other than wealthy, powerful white guys (oh, and the obligatory sections about Martin Luther King, Jr and Susan B. Anthony, of course).
I have heard many criticisms of Other Studies from those who are threatened by people learning about real things that really happened in history. Some mock Other Studies as being inherently less academic than Real History, as less important than Real History, or as contributing to some decline in "Western Civilization." In Arizona, this ban on ethnic studies is predicated on the idea that it is Mexican-Americans who are unfairly and divisively marking themselves as Other, when in reality, it is always dominant groups that mark minority groups as Other and, usually, as inferior as well.
Thus, ignorant due to their privilege, members of dominant groups are extremely uncomfortable with minority groups expressing pride in and learning about their Other-ness. Like conservative white guy Dennis Prager, who has argued that minority groups should feel "group shame," those who possess non-marginalized identities often make the ego-centric mistake of thinking that minority pride events are actually about the majority group. Thus, some anti-gays interpret LGBT pride not as a celebration of our sexual identity, but rather as an exercise in making anti-gay people feel bad about the historic mistreatment of LGBT people.
Unable to conceive of a human experience that is not centered around the experience of a heterosexual (or a man, or a white person, for instance), this is the same ego-centric logic that defines ethnic studies as racist against white people and feminism as misandrist. It is a privileged worldview that posits that expressions of Black Pride are unfair because a White Pride party would be considered racist, or that Male Studies is a necessary discipline on top of Men's Studies because it is men, really, who are oppressed and there just isn't enough shit dedicated to the male experience in life.
To possess aggressive, insecure privilege is to hold a worldview that contributes nothing but ignorance to the world, both by its denial of real things that happened in real history and it's labeling of of Other worldviews as unimportant, unreal, and unnecessarily divisive.