While it's good to see that homophobia is frowned upon, I don't think businesses should be allowed to refuse service based on the owner's personal morals, especially since there are already laws in place against certain forms of such practises (for good reason). As tempting as it is, I don't think that businesses should be allowed to do this only when I happen to agree with their cause, as that's textbook hypocrisy.
I agree with you in a sense, however to my understanding right of admission allows owners to kick people out based on personal opinion, but not to discriminate against minorities or other ethnic groups. If he had say imposed denial of service to all homophobic republicans, it could be seen as discrimination. However he is specifically denying service to a specific person based on their own feelings.
Unfortunately, the argument I present can be easily picked apart and used for normal discrimination. For example: I didn't kick him out because he was black, but because he smelled, etc.
How exactly does one effectively weigh up the differences between right of admission and non discrimination laws. They both contradict each other, and both are necessary. Where do you find the middle ground though?