The Lemon Test Explained

For decades, one three-part test shaped how courts decided whether government had crossed the line between church and state. Why did it fall out of favor, and is it really gone?

In this TalksOnLaw Brief, Sarah Barringer Gordon, the Arlin M. Adams Professor of Constitutional Law and Professor of History, Emerita, at the University of Pennsylvania Carey Law School, explains the Lemon test, the alternatives the justices tried, and its fate after Kennedy v. Bremerton School District.

The Three Prongs

Professor Gordon explains that Lemon v. Kurtzman (1971), written by Chief Justice Warren Burger, set out three requirements. First, a law must have a credible secular purpose. Her example is a multi-billion-dollar fund simply to support an order of nuns, which may lack one unless the money also supports something like feeding the poor. Second, the law's primary effect, meaning what it does most of the time, must neither advance nor inhibit religion; it should not target religion in its effect. Third, it must not unduly entangle government with religion.

Burger, she notes, was a Nixon appointee, not a liberal, and the test was meant to bring order to a messy body of law for the justices and lower court judges alike. Over time, the Court also found ways around limits on public funding, for example by sending aid to parents who choose where their children go to school, so that the choice is the parents' rather than the government's.

Why Lemon Lost Favor

The prongs were complicated and hard to square with one another, and failing any one meant a violation. Justice Sandra Day O'Connor proposed a different focus: whether government is endorsing religion, sending a message that some citizens are favored. That endorsement test became popular for a while and seemed to salvage Lemon at some level. Justice Kennedy sharply criticized it, and in Town of Greece v. Galloway (2014), a case about prayer at town meetings in Greece, New York, he concluded that the prayers posed no problem. Both tests became unpopular, Professor Gordon explains, partly because in some people's eyes the Establishment Clause had come to overwhelm the Free Exercise Clause.

After Kennedy v. Bremerton

In Kennedy, the Court ruled for a public school football coach who prayed on the field after games, and the majority said the Court had long ago abandoned Lemon and its endorsement test offshoot in favor of historical practices and understandings. Professor Gordon's verdict is that Lemon, though not formally overruled, is now “in a timeout box with a dunce cap on” in the corner. Scholars and the dissent faulted the majority for not overruling it outright, while some justices, she notes, including Justice Barrett, ask what would replace it.

What to Know Now

Lower courts now treat Lemon as no longer controlling and apply the history-and-tradition approach. In 2026 the full Fifth Circuit, voting 9-8, upheld a Texas law requiring the Ten Commandments to be displayed in public school classrooms, reasoning that Stone v. Graham (1980), which struck down a similar Kentucky law, rested on Lemon and no longer controls; the same court found a challenge to Louisiana's similar law not yet ripe. The Supreme Court has also continued to strengthen religious liberty claims, as in Mahmoud v. Taylor (2025), which recognized parents' right to opt their children out of instruction that burdens their religious exercise, and it divided 4-4 in 2025 over a publicly funded religious charter school. Supporters see a more faithful reading of the First Amendment; critics worry about less guidance for courts and less protection for students.