Judge Sandra L. Lynch, writing for the panel, said the regulation did not single out religion for disfavored treatment. In a 1990 decision, the Supreme Court ruled that neutral laws of general applicability that incidentally impose burdens on religion generally do not run afoul of the First Amendment’s protection of religious liberty. That decision, Employment Division v. Smith, has been the subject of harsh criticism by the more conservative members of the Supreme Court.

In a series of recent decisions on pandemic-related restrictions on religious gatherings, the Supreme Court also ruled that religious activities must be treated at least as well as comparable secular ones.

The plaintiffs in the case from Maine said the state was an outlier in refusing to grant religious exemptions.

“Almost every other state,” they told the justices, “has found a way to protect against the same virus without trampling religious liberty — including states that have smaller populations and much greater territory than Maine. If Vermont, New Hampshire, Alaska, the Dakotas, Montana, Wyoming, California and the District of Columbia can all find ways to both protect against Covid-19 and respect individual liberty, Maine can too.”