Last Friday, the owners of an Albuquerque photography business petitioned the U.S. Supreme Court to overturn a decision of the New Mexico Supreme Court that says they can’t refuse to do business with same-sex couples on religious grounds.

The petition is somewhat peculiar, in that it claims that Jonathan and Elaine Huguenin have a free speech rather than a religious free exercise right to turn down the business. That’s because, as the New Mexico Supremes made abundantly clear, the current constitutional rule is that you have no free exercise appeal against a neutral and generally applicable state law.

According to New Mexico law, you can’t discriminate against people because of their sexual preference. What the Huguenins claim is that being obliged to undertake the (artistic) photography is “compelled speech.”

Let’s leave this jurisprudential nicety aside. The underlying question is: Should Americans be able to use their religious scruples to refuse to provide commercial services to same-sex couples?

Any answer cannot turn on a court’s assessment of the worth of the scruples — whether the particular religious objection is justified or not. All that the American judiciary is entitled to determine is the sincerely of whoever is making the claim. Thus, writing for the court in Bob Jones v. United States (1983), Chief Justice Warren Burger found that the “sponsors of the University genuinely believe that the Bible forbids interracial dating and marriage.” Even so, an eight-justice majority found that racial equality trumped religious liberty, and the IRS’ decision to take away Bob Jones’ tax deduction was sustained.

If we don’t recognize a religious right to discriminate against, say, the newly elected first family of New York City, why should we recognize a religious right to discriminate against a same-sex couple? Why should the latter be more legally tolerable than the former?