It is important to note that Madison was making this case not in the context of arguing for permitting the free exercise of religion but rather in the context of arguing against the establishment of any religion by law. His point was that no one ought to be compelled to affirm as true a religious tenet he took to be false and that no one should be compelled to participate in a religious rite that violated his own understanding of his religious obligations. This is not exactly an extension of the traditional Anglo-American case for toleration. It is a Madisonian correction to the Lockean ideal of religious toleration in a society with an established church.
But this is also the essence of the argument that a wedding vendor who wants to remain free to refrain from participating in a same-sex wedding would advance. The question of the definition of marriage is, for many people, a fundamentally religious question. It is, of course, also a civil question in our country. But some religiously orthodox wedding vendors are finding themselves effectively compelled by the civil authorities to affirm an answer to that question that violates their understanding of their religious obligations. They would like to be relieved of that compulsion, but they are being told they can’t be because the larger society’s understanding of the proper answer to the question should overrule the answer prescribed by their religious convictions, and if they want to participate as business owners in the life of the larger society they must give ground.