The Supreme Court on Tuesday hears oral arguments in a case that could determine whether businesses can withhold services from gay couples, citing religious beliefs. The controversial case concerns Colorado baker Jack Phillips, owner of Masterpiece Cakes, who declined to make a custom wedding cake for a same-sex couple. Phillips' lawyers say he "gladly serves people from all walks of life, including individuals of all races, faiths, and sexual orientations. But he cannot design custom cakes that express ideas or celebrate events at odds with his religious beliefs." The couple, David Mullins and Charlie Craig, said Phillips violated a state law guaranteeing them "the same full and equal service" other customers get, and lower courts have sided with them.