The Supreme Court’s decision last week overturning New York State’s limits on religious gatherings during the COVID-19 outbreak previewed what will likely become one of the coming decade’s defining collisions between law and demography.

The ruling continued the conservative majority’s sustained drive to provide religious organizations more leeway to claim exemptions from civil laws on the grounds of protecting “religious liberty.” These cases have become a top priority for conservative religious groups, usually led by white Christians and sometimes joined by other religiously traditional denominations. In this case, Orthodox Jewish synagogues allied with the Roman Catholic Diocese of Brooklyn to oppose New York’s restrictions on religious services.

But this legal offensive to elevate “religious liberty” over other civic goals is coming even as the share of Americans who ascribe to no religious faith is steadily rising, and as white Christians have fallen to a minority share of the population.

That contrast increases the likelihood of a GOP-appointed Court majority sympathetic to the most conservative religious […]