But Kennedy explained where his principle came from: "A test that would sweep away what has so long been settled," he wrote, "would create new controversy and begin anew the very divisions along religious lines that the establishment clause seeks to prevent." If the purpose of the establishment clause is to avoid divisiveness along religious lines, as Justice Stephen Breyer (today a dissenter) has in the past argued, then according to the court, the clause itself should not be interpreted in such a way as to create further controversy.
Kennedy then dismissed the argument that legislative prayer is only constitutional if nonsectarian, pointing out accurately that legislative prayer in Congress has often been sectarian in the past, even if today prayer leaders are urged to adopt a nonsectarian tone.
Next, in a portion of the opinion that commanded only a plurality, Kennedy applied his own favored establishment clause test - whether the government action coerced anyone to participate in religious activity against his or her will, even subtly. (Disclosure/humblebrag: I've also written extensively in favor of coercion as an establishment clause test, alongside a prohibition on government expenditure of funds, and Kennedy cited my work in his opinion.)
On the facts, Kennedy concluded, the town wasn't coercing anyone by holding prayers before council meetings. Those in attendance were, he stressed, "mature adults" who were free to come and go and avoid the prayers if they wished. With this observation, he distinguished the case from a famous 1992 case, Lee v. Weisman, in which he wrote the opinion striking down a nondenominational prayer offered by a rabbi at a middle-school graduation ceremony. Many (myself included) have long speculated that Kennedy would distinguish children, susceptible to peer pressure, from adults - and Monday he confirmed that speculation.
Justice Clarence Thomas, joined by Justice Antonin Scalia, wrote separately to offer a new and significantly improved version of his idea that the establishment clause applies only to the federal government, not the states. In the past, Thomas had appeared to subscribe to the historically implausible view that the words "Congress shall make no law respecting an establishment of religion" were actually intended to protect state establishments of religion from congressional action. The framers' generation considered "establishment" a dirty word, and Thomas thankfully now appears to have jettisoned that view in favor of the claim that, because the First Amendment was originally intended to apply only to the federal government (leaving matters connected to religion to the states), it therefore should not be applied to the states like the rest of the Bill of Rights. While I don't agree with the conclusion, this perspective at least deserves respect, based as it is on credible history.
Justice Elena Kagan wrote the principal dissent, which itself should count as a landmark. For essentially the first time in the court's history, she offered a full-throated defense of religious "pluralism and inclusion" as a constitutional value. Kagan argued that a town hall "need not become a religion free zone." In her view, because the prayers offered in Greece were overwhelmingly Christian, the government had "aligned itself with a particular religious creed" in violation of the establishment clause. She offered a series of hypotheticals involving a court, an election and a naturalization ceremony in which sectarian prayers would, she said, violate the establishment clause.
That left her with the problem of the Marsh precedent, which she purported to accept as binding. She differentiated the legislative prayer in Nebraska which wasn't always nonsectarian by saying that the Greece town council meetings were not simply legislative, but were also "also occasions for ordinary citizens to engage with and petition their government, often on highly individualized matters." In that sense, the meetings resembled court cases more than legislative sessions and this required the town to exercise "special care" to achieve inclusivity.
What's most original about the dissent is its view that explicit invocation of religion would have been permissible so long as all religions were included. This conclusion is, I think, correct as a political and ethical matter religious pluralism reduces religious conflict, sectarianism increases it. But making it a constitutional principle is exceedingly risky. Who decides just how much religious pluralism is enough, and which denominations need to be included? Kagan's rule wouldn't be administrable as a majority opinion. It would put the courts in the position of refereeing religious pluralism.
If the town of Greece wants to open its council meetings with prayers, it really should be inclusive. But Kennedy's plurality opinion got it right. So long as no one is coerced, inclusiveness is a political virtue but not a constitutional requirement.
Noah Feldman is a professor of constitutional and international law at Harvard University and the author of six books.