You are correct that supporting a political candidate is a personal choice, and on many occasions I continue to do business with companies headed by people who back political ideals I disagree with. However, I HAVE discontinued business with companies that directly support groups I disagree with (Chick-fil-a being a small, but easy example) - I don't care what people do with their own funds, but once a companies name is attached to a donation or lobbying effort it's completely reasonable to hold them accountable for their actions in my eyes.

Unfortunately, even with this mental separation I try to maintain it falls into shades of gray when there isn't a clear separation between the business and the individual.