The plurality opinion was written by Justice Alito, who was joined by Chief Justice Roberts and Justice Kennedy. Here are excerpts from the Court's syllabus of that opinion:
The link between congressional action and constitutional violation that supported taxpayer standing in Flast is missing here. Respondents neither challenge any specific congressional action or appropriation nor ask the Court to invalidate any congressional enactment or legislatively created program as unconstitutional. That is because the expenditures at issue were not made pursuant to any Act of Congress, but under general appropriations to the Executive Branch to fund day-to-day activities. These appropriations did not expressly authorize, direct, or even mention the expenditures in question, which resulted from executive discretion, not congressional action. The Court has never found taxpayer standing under such circumstances....Justice Kennedy also wrote a separate concurrence in which he said: "It must be remembered that, even where parties have no standing to sue, members of the Legislative and Executive Branches are not excused from making constitutional determinations in the regular course of their duties. Government officials must make a conscious decision to obey the Constitution whether or not their acts can be challenged in a court of law and then must conform their actions to these principled determinations."
Respondents argue to no avail that distinguishing between money spent pursuant to congressional mandate and expenditures made in the course of executive discretion is arbitrary because the injury to taxpayers in both situations is the same as that targeted by the Establishment Clause and Flast-- the expenditure for the support of religion of funds exacted from taxpayers. But Flast focused on congressional action, and the invitation to extend its holding to encompass discretionary Executive Branch expenditures must be declined....
Taking the Circuit’s zero-marginal-cost test literally-- i.e., that any marginal cost greater than zero suffices-- taxpayers might well have standing to challenge some (and perhaps many) speeches by Government officials. At a minimum, that approach would create difficult and uncomfortable line-drawing problems.
Justice Scalia, joined by Justice Thomas, concurred. Here are excerpts from the syllabus of that concurrence:
A taxpayer’s purely psychological disapproval that his funds are being spent in an allegedly unlawful manner is never sufficiently concrete and particularized to support Article III standing.... Although overruling precedents is a serious undertaking, stare decisis should not prevent the Court from doing so here. Flast was inconsistent with the cases that came before it and undervalued the separation-of-powers function of standing. Its lack of a logical theoretical underpinning has rendered the Court’s taxpayer-standing doctrine so incomprehensible that appellate judges do not know what to make of it. The case has engendered no reliance interests. Few cases less warrant stare decisis effect. It is past time to overturn Flast.Justice Souter wrote a dissent in which Justices Stevens, Ginsburg and Breyer joined. They said, in part:
Here, the controlling, plurality opinion declares that Flast does not apply, but a search of that opinion for a suggestion that these taxpayers have any less stake in the outcome than the taxpayers in Flast will come up empty: the plurality makes no such finding, nor could it. Instead, the controlling opinion closes the door on these taxpayers because the Executive Branch, and not the Legislative Branch, caused their injury. I see no basis for this distinction in either logic or precedent....
