Generally in America non-citizens are not considered to be a "minority" for these purposes. This is somewhat strange for someone like my wife, who will qualify as a minority in about 3 years when/if she gets her citizenship =).
This being said, they can't/won't (hardly matters) keep you from attending something because you aren't a minority. They may try to guilt you into no "stealing a spot" from some "needy" person, but they won't stop you. It would be FAR too politically incorrect. I'm not sure what the exact laws are on this, but this seems to be the "de-facto" situation. Non-minorities don't cry foul as long as we are allowed to attend!
Welcome to Racial politics in America. Let the fun begin!