A new law took effect in Louisiana earlier this year that requires pornographic websites to age-verify their users. The purpose of Act 440 is to prevent kids from accessing explicit content: a worthy goal, even if most teens will probably be tech-savvy enough to get around the rule. The law should at least prevent younger kids from accidentally stumbling onto such content, which is a good thing: Anyone who has seen a four-year-old use an iPad knows how quickly they get into things they shouldn’t.

The bill is also a good example of how conservative state governments can create legal pathways to push back against moral decay. A similar law in Utah led to PornHub entirely restricting access in the state. Other regulations can have ripple effects beyond just the state enacting them, like California’s vehicle-emissions standards, which set terms for the entire car industry. Laws like Louisiana’s, especially when enacted by a collection of conservative states in concert, could have similarly broad effects.

A federal lawsuit filed last week alleges that the law infringes on the First Amendment, never mind the fact that the law doesn’t prevent adults from exercising their supposed right to watch porn. According to Slate, at least one plaintiff thinks that the law might violate “the separation of church and state” because Christian groups helped promote the bill. The Court’s evaluation of blue laws is instructive in showing why this claim falls flat. In a rare moment of constitutional accuracy, Chief Justice Warren wrote in McGowan v. Maryland that “the ‘Establishment’ Clause does not ban federal or state regulation of conduct whose reason or effect merely happens to coincide or harmonize with the tenets of some or all religions.” Protecting minors from the darker corners of the Internet is clearly such an effect, as the plaintiffs in the case were forced to admit, even if they don’t think the law is tailored narrowly enough.

Warren went even further, clarifying that legislation “will have no less weight if they are shown to be in accordance with divine law.” The courts should take Warren’s words to heart when they review Act 440. The First Amendment does not restrict states from passing laws on the grounds that religious people might agree with them.