Does a bar have a right to refuse service to a gay couple? Does a restaurant have a right to refuse service to an Asian man? Does an airline have a right to ref

Does a bar have a right to refuse service to a gay couple? Does a restaurant have a right to refuse service to an Asian man? Does an airline have a right to refuse service to a black person? There are sometimes quite compelling reasons to require private companies to provide services aimed at the public without discrimination.