If the owner of my neighborhood coffee shop had gone on record as supporting SOPA/PIPA/et al, I would be strongly inclined to stop going to that coffeeshop and giving them any of my money. I would also tell my friends about the situation so that they might also take similar actions if they felt so inclined.
I can tell you that, in the context of this hypothetical situation, any arguments that my actions are uncalled-for because "coffee has nothing to do with the Internet" would not have much impact on me.