When they hail religious liberty, they do not mean the right to pray and worship with other believers. Instead, the phrase has become a catchall for tactical goals of seeking exemptions from the law on religious grounds. To claim exception from the law as a right of “religious refusal” is, of course, the same as claiming the power to take the law into one’s own hands.

The leaders of this movement are breathtakingly radical. Like Mr. Swanson, they feel persecuted and encircled in a hostile world. Like him, they believe that America will find peace only when all submit to the one true religion.

True, few share Mr. Swanson’s taste for genocidal fantasy. But they do share the ultimate goal of capturing the power of the state and remaking society in ways most Americans would find extreme: a world in which men rule in families, women’s reproductive freedom is curtailed and “Bible believers” run the government.

This movement is a power to be reckoned with in Republican Party politics. Mr. Cruz, for one, is basing his strategy on winning its support. Ben Carson told a Liberty University convocation this month of his concern that so many people “are trying to push God out of our lives.” And early this year, Mr. Jindal hosted a religious revival rally on the Louisiana State University campus that was sponsored by the American Family Association.

But the real influence of the movement is in the less visible realm of state legislatures. In 2015 alone, 87 religious refusal-related bills were introduced in 28 states.

All of this raises some unsettling questions about political life in the United States. When presidential candidates court support among the audience of a pastor who openly discusses the extermination of millions of their fellow citizens, why is this not major news?