School choice advocates often must tiptoe around their own state constitutions. Many contain bans on aid to certain groups. Opponents cite those bans to claim school choice is unconstitutional. Courts sometimes agree.

But some of those bans violate the First Amendment because they were designed to mandate state discrimination against religious minorities. The United States Supreme Court has one under review right now.

The case involves a decision by the highest court of Montana. The state legislature passed a law allowing small tax credits for Montanans donating to school scholarship foundations. But the Montana court voided the law because the measure allowed the recipient foundations to give scholarships to religious school students as well as secular school students.

If this Montana ruling sounds bizarre, it is: This may be one reason SCOTUS quickly agreed to review the case. But other courts have used state constitutions to achieve similar, if less extreme, results.

The state constitutional provisions employed to attack religious schools frequently are called “Blaine Amendments” — although as explained below, that label is not quite accurate. Thirty-seven state constitutions contain them.

James G. Blaine was a 19th century statesman who served as speaker of the House of Representatives, a senator, and secretary of state. He was the 1884 Republican nominee for president

In 1875 Blaine proposed an amendment to the U.S. Constitution. Some claim he was targeting Catholic schools, but that probably was not true. Blaine certainly was not anti-Catholic: His mother was Catholic and he may have been baptized in that faith. Blaine even spoke out publicly (although not strongly) against anti-Catholic bigotry. His proposed amendment would have treated all religious denominations equally.

But other politicians openly catered to religious prejudice. As a result, today the constitutions of 26 states contain bans that go well beyond what Blaine wanted. Unlike Blaine’s proposal, those constitutions mandate discrimination against “sectarian” religion.

Today many people think the word “sectarian” is merely a synonym for “religious.” But until fairly recently “sectarian” was a pejorative term used to brand religious minorities. If you said a religious group was sectarian, you were saying it was bigoted, heretical, or at least out of the mainstream. That is how dictionaries defined the word.

Protestants often tarred Roman Catholics as “sectarian.” Additional victims of the epithet were Mormons, Jews, Muslims, and other religious minorities. One way to praise a religious group or doctrine was to say it was NOT sectarian.

For example, the president of Harvard College defended his institution by saying that although Unitarians controlled Harvard, Unitarianism was not a sectarian religion. He also listed several other Protestant denominations as non-sectarian based on their theology, That led a newspaper editor to conclude that Muslims and Catholics were sectarian.

In 1927 the Colorado Supreme Court made a similar division by holding that the Protestant King James Version of the Bible was non-sectarian, and could be taught in public schools.

One reason for bans on aid to “sectarian” institutions was to secure a funding monopoly for the Protestant-leaning public schools. Another reason, apparently, was to give lawmakers and courts a tool for denying funds to institutions controlled by disfavored religious minorities.

The Montana provision is a good example. In 1889, a convention drafted the state’s first constitution, adding a ban on aid to “sectarian” institutions. Dictionaries then defined “sectarian” as designating religious zealots, bigots, and heretics. Newspapers, including Montana papers, used it the same way. The term was employed in a pejorative manner even on the convention floor.

In 1972, a new Montana convention gathered to produce a new state constitution. It debated whether to retain the prohibition on aid to “sectarian” schools. At this time also, dictionary definitions were still overwhelmingly negative, and Montana newspaper articles continued to discriminate between sectarian and non-sectarian religion.

To their credit, some of the 1972 convention delegates urged that the bigoted prohibition be removed.

Astoundingly, however, the convention voted to retain the anti-sectarian language almost unchanged. Indeed, they doubled down — trumpeting that the new provision would have the same legal effect as the old. During the ensuing ratification campaign, both official and unofficial sources told voters the same thing.

Imagine if a state constitution said that free speech was protected, but prohibited state benefits to “extremists.” Obviously, the justices would invalidate this as contrary to the First Amendment.

State constitutional bans against aid to “sectarian”schools deserve precisely the same fate.

Rob Natelson is senior fellow in Constitutional Jurisprudence at the Independence Institute in Denver. He formerly taught constitutional law and First Amendment law at the University of Montana. He is the author of Why Nineteenth Century Bans on “Sectarian” Aid Are Facially Unconstitutional: New Evidence on Plain Meaning, 19 Fed. Soc. Rev. (2018).