What case allowed congress to regulate the drinking age within the states using the tax and spending clause of article i?

South Dakota v. Dole

In 1984, Congress passed legislation requiring the Secretary of Transportation to withhold five percent of federal highway funds from states that did not adopt a 21-year-old minimum drinking age. South Dakota challenged the law. In a 7-to-2 decision, the Court held that Congress, acting indirectly to encourage uniformity in states' drinking ages, was within constitutional bounds.