Whether the physician-plaintiffs had Article III standing to challenge Missouri's Medicaid exclusion because they suffered a concrete injury of their own.
Holding
Yes. The physicians alleged a direct financial injury sufficient to create an Article III case or controversy.
Reasoning
The physicians alleged that they performed and would continue to perform abortions for Medicaid-eligible women, and that Missouri would reimburse them for those services but for the restriction on funding nonmedically indicated abortions. If they prevailed, they would receive payment; if Missouri prevailed, they would not. That direct economic stake made the parties classically adverse.
Article III standing asks whether the plaintiff has a concrete personal interest in the litigation's outcome. The doctors' claimed loss of reimbursement was not speculative or merely ideological, so the Court had constitutional power to hear their challenge.