This isn’t the same as a regular corporate event. It is a political event giving a platform to a group that is very opposed to a large chunk of your customer base and is aiming at closing off a decent portion of public park space for the benefit of a few very wealthy people. You should always investigate political groups seeking to utilize your venue.

Your response makes sense as a regular person. You aren’t a regular person in this situation, though. You are a member of the community and depend on that community for your business and employees. Given the pain already felt due to rampant inflation and the pandemic, and given the darker economic situation on the horizon, it would be prudent to consider the longer term effects of your actions. Recessions decimate discretionary income. Breweries are very much dependent on discretionary income. This isn’t a good time to alienate patrons.