South Dakota v. Dole

Majority reasoning

The Court reasoned that Congress's spending power lets it attach conditions to federal grants to further broad policy goals, even in areas outside its direct regulatory authority, as established in cases like United States v. Butler. It found the condition served the general welfare because Congress determined that differing state drinking ages encouraged young people to drive to lower-age states and then drive back, creating a highway safety problem tied directly to interstate travel, one of the purposes for which highway funds are spent. The condition was unambiguous, and South Dakota did not seriously dispute that it was related to a national highway safety concern. On the Twenty-first Amendment question, the majority held that the "independent constitutional bar" limitation on spending conditions only prevents Congress from inducing states to take actions that would themselves be unconstitutional (like discrimination), not from encouraging policies Congress could not mandate directly; since South Dakota raising its drinking age would violate no one's rights, this bar did not apply. Finally, the majority concluded the financial pressure was not unconstitutionally coercive, since South Dakota stood to lose only 5% of certain federal highway funds, calling this "relatively mild encouragement" rather than compulsion.

Dissent reasoning

Justice Brennan, joined by no one but noting agreement with Justice O'Connor, argued briefly that regulating the minimum age for alcohol purchasers falls squarely within powers reserved to the states by the Twenty-first Amendment, so Congress cannot condition a federal grant in a way that abridges this state authority. Justice O'Connor, dissenting separately, agreed with much of the majority's spending power framework but argued the Court applied the "reasonably related" requirement too loosely: a national drinking age of 21 is not sufficiently connected to highway construction funding to justify conditioning those funds on it. She argued the condition is both over-inclusive, stopping young people from drinking even when they won't drive on highways, and under-inclusive, since statistics showed most alcohol-related highway fatalities involve people over 21. O'Connor warned that if this loose a connection were sufficient, Congress could use highway funding to regulate almost any aspect of state life, and argued the true purpose of the law was to regulate liquor sales rather than to determine how highway funds are used—something reserved to the states by the Twenty-first Amendment and not authorized by the commerce power in this area.