If there is a local non-discrimination law in place -- re public accommodations -- then they can't discriminate. This is a major effort of lgbtq activism, to ensure that we aren't turned away from restaurants and businesses for being gay. In the town i lived in, the printer nearest to the university where student groups got their flyers and such printed up refused to print for lgbtq student groups. The reaction ultimately resulted in a non-discrimination ordinance. Here is a link to the ordinance. i remember the day it was passed. i was at the city counsil meeting. A very good day.
http://www.genderadvocates.org/polic...Ordinance.html