How to cut the cake

Supreme Court justices were right Monday to invalidate a fine on a baker who had refused to create a custom wedding cake for a same-sex couple. And they were right to slice the law as thinly as possible — on the cautious ground that Colorado’s Civil Rights Commission had in this particular case exhibited overt hostility to Jack Phillips’ religious freedom, thereby invalidating the fine it had imposed on him.

What for now goes legally and unconstitutionally unresolved is whether the wide array of artisans who participate in a wedding ceremony and party are allowed to opt out of participating in gay and lesbian unions on the ground that they are opposed as a matter of biblical conscience.

On this question, carveouts must be as narrow as possible. Venue owners, citing religious beliefs, might seek to flatly prohibit parties in which men marry men, or women women. Caterers, florists and makeup artists, tailors and dressmakers, too.

That ought not be permitted under the Constitution’s guarantee of equal protection under the law, just as in the vast majority of cases, businesses cannot flatly refuse to serve interreligious or interracial marriages.

The toughest cases involve people whose job is purely expressive: the wedding singer, perhaps the cake maker if he or she is asked to write words on top. In America, no one who objects to samesex marriage on religious grounds can be forced to attend or endorse one. But neither should that very specific objection turn into a license for rampant discrimination.

We don’t pretend the line is easy to draw.