Lana, I am going to indulge in a hyperbolic example here, and use it to ask you a few direct questions. It's not necessarily realistic, and I'm not saying that your argument invariably leads to this, so it's not a slippery slope. It might be a bit reductio ad absurdum, but I'm also not saying that you are necessarily supporting this.
So. A man owns a clothing store. Among other things, they sell T-shirts. Note, please, this is not a secondhand store. One day, a person comes in, wants to sell a shirt emblazoned with an black eagle holding a black wreath. Encircled in the wreath is a black swastika on a white background. Above this is the word Sieg. Below is Heil. On the back is an image of Hitler and a bunch of silhouettes saluting him, in the manner that is their custom. Is the man obligated to order a hundred of these shirts and sell them? What if he's black? Jewish? Roma? Gay? Any combination of these? Is he still obligated to do it?
Now, say the shirts aren't full of hate. Say, instead, that they're ratty, with holes worn or chewed in them. Is he obligated to sell them in his store? What if the shirts are obviously stolen? What if they're none of these, but the images of them aren't hateful, just... not his? (For example, what if the image is Mickey Mouse, and this man is not at all a representative of the Disney corporation. He's Joe Blow from the trailer park with 2 DUIs and who got busted for meth a while back. He don't work for Disney.) When, if ever, can someone refuse to carry a product?