The ban on religious tests was a major source of contention during the debates to ratify the new constitution. Madison wrote to Jefferson in 1788 that “one of the objections in New England was that the Constitution, by prohibiting religious tests, opened a door for Jews, Turks & infidels.” Indeed, a delegate to Massachusetts’ ratifying convention warned that public office would be open for “a papist or an infidel.”

During North Carolina’s 1788 ratification debate, anti-Federalist Henry Abbot argued that having no religious test meant it would be possible that “pagans, deists and Mahometans might obtain offices among us, and that the senators and representatives might all be pagans.” A South Carolina newspaper warned that Quakers might take over the fledgling government.

Defenders of banning a religious test fired back. Baptist preacher John Leland, who had opposed religious tests successfully in Virginia, argued, “If a man merits the confidence of his neighbors in Virginia, let him worship one God, 20 Gods or no God — be he Jew, Turk, Pagan or Infidel, he is eligible to any office in the state.”

And Federalist James Iredell, who subsequently was appointed to the Supreme Court, stood firm in his defense of the clause: “[It] is objected that the people of America may, perhaps, choose representatives who have no religion at all, and that pagans and Mahometans may be admitted into offices. But how is it possible to exclude any set of men, without taking away that principle of religious freedom which we ourselves so warmly contend for?”