We have 3 nice Mexican restaurants close to our house, and we frequented them all. Two of them were open yesterday, one was closed. We will never again go to Las Palmas Mexican Restaurant on Wade Green Road (just off I-75), in Kennesaw, GA.
You need to go one more time to tell them why. Or at least send a letter.
We have a very good Mexican restaurant near our business. It is run by Christians (fish symbol on ads and such), and was closed Monday as it is every Monday. Be sure that the one you cite was closed in "solidarity" with the protest and not just because it was Monday.