> The US federal government can pass laws directly binding on the citizens of every state, but cannot compel state governments to pass and enforce particular laws.
Only in theory.
See the National Minimum Drinking Age Act[0] for an example of when the Federal Government forced states to enforce a age 21 drinking minimum. When an entity controls the purse strings limits on their power are largely theoretical.
The National Minimum Drinking Age Act didn't "force states" to do anything. It provided that the federal government would withhold 10% of highway funds if states did not enact a drinking age of 21--it had to use a carrot/stick approach precisely because the federal government could not directly compel states to legislate.
That distinction, moreover, is not "theoretical"--it is a limit on federal power that has real teeth. In NFIB v. Sebelius, a majority of the Supreme Court (7-2, on that point) held that ACA's Medicaid expansion was "unconstitutionally coercive" because it would allow the federal government to withdraw all of a state's Medicaid funding if the state did not expand Medicaid eligibility under state law.
Gay marriage, drugs, and immigration are other significant areas where states have used their prerogatives to depart from and refuse to enforce federal law.
That distinction, moreover, is not "theoretical"--it is a limit on federal power that has real teeth. In NFIB v. Sebelius, a majority of the Supreme Court (7-2, on that point) held that ACA's Medicaid expansion was "unconstitutionally coercive" because it would allow the federal government to withdraw all of a state's Medicaid funding if the state did not expand Medicaid eligibility under state law.
Gay marriage, drugs, and immigration are other significant areas where states have used their prerogatives to depart from and refuse to enforce federal law.