An Arizona gun shop has posted a sign on its door that warns customers that if you voted for Obama "turn around and leave." The owner states that anyone who voted for Obama has proven they aren't responsible enough to own a gun.
This is where anti-Obama citizens can exact their power--they are the business owners and--in most states--they have the ability to refuse service to customers. Is it possible to precisely enforce this, no. But in this case, the message is at least as strong as the potential for action. The gun shop owner holds all of the cards here--admit you voted for Obama and he can use his power not to sell to you. Don't admit that you voted for Obama and buy something--money in the owner's pocket.
The owner also took out a full-page ad expressing his sentiment in the local newspaper.