State Power and the Conscience of the Individual

Why shouldn't the state have and exercise the power to override the conscience of the individual?  Suppose I am in the bumper sticker and T-shirt business.  You come to my shop and order a thousand Fuck Obama! bumper stickers and a thousand Hillary Sucks! T-shirts.  I explain to you that to do as you request would be to violate my longstanding commitment to civility  and that you should take your business elsewhere.

Question: Should the power of the state be used to force me to serve this particular customer?  If not, why not?  Am I not discriminating against him on the basis of his creed, which includes a commitment to the absolute right of free speech?  Am I not interfering with his exercise of this absolute right?

"Fuck Obama" Bumper Sticker