CM: First, who wants to give a business, carrying out a commercial transaction, authority of approval? Should fat people not be allowed to buy iPhones because they make the technology look unattractive? Should book stores refuse to sell to people who wear crosses around their necks because the bookseller doesn't approve of religious garb?
VR: The answer to this involves a distinction between commercial services that provide expression, or speech, on behalf of gay weddings, and those that don't. For the former, I there is a problem with a business putting a sign up in their hardware store that says "no gays." (So if a gay person needs a screw, they have to get it somewhere else). However, businesses that provide celebratory expression should be able, if this is a stated policy, to provide that expression only if that is what they support. If you are a professional speechwriter, should you be accused of discrimination if you will only provide your services for Republican candidates and not Democratic candidates?
Apologies for the bad pun.