Trump v. California · ¶26

The States cannot preemptively concretize their injury by expending funds before the Postal Service finalizes a rule. Spending money to hedge against a “speculative threat” does not constitute an Article III injury. Clapper, 568 U. S., at 416. Though it may sometimes be “a reasonable reaction” to “incu[r] certain costs” in advance of a final rule, those costs cannot establish standing when the final rule remains a “hypothetical future harm that is not certainly impending.” Ibid. Federal courts review final rules, not proposed rules—and certainly not antecedent internal directives to propose a rule. If the Postal Service’s final rule harms the States, they may challenge that rule.

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