In 1984, Congress enacted legislation ordering the Secretary of Transportation to withhold 5 percent of federal highway funds from states that did not adopt a 21-year-old minimum drinking age. South Dakota, a state that permitted persons 19 years of age to purchase alcohol, challenged the law. In South Dakota v. Dole (1987), the Court delivered a 7 to 2 decision that held that Congress, acting indirectly to encourage uniformity in states' drinking ages, was within constitutional bounds. The Court found that the legislation was in pursuit of "the general welfare," and that the means chosen to do so were reasonable. The Court also held that the constitutional limitations on spending power were not prohibitions on congressional attempts to achieve federal objectives indirectly. The 5 percent loss of highway funds was not excessive.
Source: Oyez, South Dakota v. Dole (1987)

(A) Identify the constitutional clause that is common to both South Dakota v. Dole (1987) and United States v. Lopez (1995).

(B) Based on the constitutional clause identified in part A, explain why the facts of United States v. Lopez led to a different holding than the holding in South Dakota v. Dole.

(C) Explain how the holding in South Dakota v. Dole affected the balance of power between the states and the national government.