Thanks for the replies & to the people that sent me PMs.
I checked with the BBB & they don't service cases of possible discrimination & the ACLU site says that it may take several weeks for a case review. I will contact some of the press that you have mentioned. I don't think I will contact a lawyer just yet as I would prefer to await a response from McDonalds & the franchise company. I will also be contacting the airport people tomorrow when they are open.
Dovster - I didn't notice a sign at this particular location, but at other establishments, I have seen signs that have said "We reserve the right to refuse service." - I don't know if that really is a right or if it's just a sign though.