School choice plans are proliferating around the nation, and today the Supreme Court will hear a case that could stop them cold on dubious legal grounds. In Arizona Christian School Tuition Organization v. Winn, the question is whether a scholarship tax credit program that has operated in Arizona since 1997 violates the First Amendment's clause that "Congress shall make no law respecting an establishment of religion."

Arizonans can receive a tax credit of $500 ($1,000 for couples filing jointly) for donations they make to so-called school tuition organizations, which operate as charities and provide scholarships to private schools. Arizona parents may then apply to use the tax-credit funded scholarships for their children at either a secular or religious school.

Last year in Arizona, the choice program provided 27,000 scholarships to 373 secular and religious private schools, overwhelmingly for children who could not otherwise afford to attend. Until recently, scholarship eligibility was not means-tested, but according to a study by the Pacific Research Institute, 67% of all scholarship recipients would qualify under a similar program that did measure families' financial situations.

As a legal matter, the Arizona case isn't a close call. The fact that it is being heard at all reflects the liberal dogmatism of the Ninth Circuit even in the face of clear Supreme Court precedent, and we hope the Justices knock this one clear out of the ballpark and all the way back to San Francisco.

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