At least four considerations show that retaining established, religiously expressive monuments, symbols, and practices is quite different from erecting or adopting new ones. First, these cases often concern monuments, symbols, or practices that were first established long ago, and thus, identifying their original purpose or purposes may be especially difficult.... Second, as time goes by, the purposes associated with an established monument, symbol, or practice often multiply.... Even if the monument’s original purpose was infused with religion, the passage of time may obscure that sentiment and the monument may be retained for the sake of its historical significance or its place in a common cultural heritage. Third, the message of a monument, symbol, or practice may evolve.... Familiarity itself can become a reason for preservation. Fourth, when time’s passage imbues a religiously expressive monument, symbol, or practice with this kind of familiarity and historical significance, removing it may no longer appear neutral, especially to the local community. The passage of time thus gives rise to a strong presumption of constitutionality.Another portion of Justice Alito's opinion was joined only by Chief Justice Roberts and Justices Breyer and Kavanaugh. They explicitly rejected the notion that the Lemon test should be applied to all Establishment Clause challenges, saying that instead the Court has sometimes used other approaches.
Justice Breyer filed a separate concurrence joined by Justice Kagan, saying:
The case would be different, in my view, if there were evidence that the organizers had “deliberately disrespected” members of minority faiths or if the Cross had been erected only recently, rather than in the aftermath of World War I.... Nor do I understand the Court’s opinion today to adopt a “history and tradition test” that would permit any newly constructed religious memorial on public land.Justice Kavanaugh wrote a concurring opinion in which he said that the majority was applying a "history and tradition" test.
Justice Kagan also filed a concurring opinion, explaining why the portions of Justice Alito's opinion which she did not join go too far in rejecting the Lemon test.
Justice Thomas filed an opinion concurring only in the judgment, and taking the position that the Establishment Clause applies only to the federal government and is not incorporated by the 14th Amendment to apply to the states. He went on to contend that even if the Establishment Clause does apply to the states, the Bladensburg Cross is constitutional.
Justice Gorsuch wrote a separate opinion concurring in the judgment, joined by Justice Thomas. He argues that the American Humanist Association lacks standing, and rejects the "offended observer" theory of standing.
Justice Ginsburg, joined by Justice Sotomayor, wrote a 20-page dissent, saying in part:
As I see it, when a cross is displayed on public property, the government may be presumed to endorse its religious content....
The Commission urges in defense of its monument that the Latin cross “is not merely a reaffirmation of Christian beliefs”; rather, “when used in the context of a war memorial,” the cross becomes “a universal symbol of the sacrifices of those who fought and died.”... The Commission’s “[a]ttempts to secularize what is unquestionably a sacred [symbol] defy credibility and disserve people of faith.”AP reports on the decision. SCOTUSblog has further analysis of the decision.