“We asked for a cake,” Mr. Craig said. “We didn’t ask for a piece of art or for him to make a statement for us. He simply turned us away because of who we are.”…

Mr. Craig said the free speech argument was a smoke screen. “It’s not about the cake,” he said. “It is about discrimination.”

If a bakery has a free speech right to discriminate, gay groups contend, then so do all businesses that may be said to engage in expression, including florists, photographers, tailors, choreographers, hair salons, restaurants, jewelers, architects and lawyers. A ruling for Mr. Phillips, they say, would amount to a broad mandate for discrimination.