Hoisted from Comments: Coercion of the States Edition by DeLong

Matt writes:

Live by the Technicality, Die by the Technicality: Orin Kerr on the ACA Decision: And that drinking age requirement [that states raise their drinking ages to 21 or have their federal interstate highway funds pulled] was enacted by none other than the sainted Ronald Reagan, and then upheld by none other than Antonin Scalia and William Rehnquist in a 7-2 SCOTUS ruling. Furthermore, it's worth noting that the 21st Amendment has always been held as giving the states the power to regulate alcohol. So unlike Medicaid, it's a federal encroachment on a power explicitly reserved to the states.