1984–1987
South Dakota v. Dole and the Federal Drinking Age
Congress tied a sliver of federal highway funds to states raising the drinking age to 21. South Dakota sued, arguing this violated states’ rights and the Twenty‑First Amendment, but the Supreme Court upheld the law as a permissible condition on spending.
Then
Most states raised their drinking ages to avoid losing funds, cementing 21 as the national norm.
Now
The case became the blueprint for using conditional federal grants to steer state policy without directly rewriting state law.
Why this matters now
Trump’s threat to withhold broadband money uses the same spending-power logic, but on a far larger and more contested scale.