| > What would compel a State to recognize any new Federal ID in the future if they already have the power to disregard Federal IDs in theory and practice? The same thing Congress does to add a workaround for any law it's constitutionally forbidden to enforce on the States. A "voluntary" program where states that don't agree to the ID law don't get any federal highway funds that year. This has been extensively tested and the Supreme Court is fine with it, e.g. [0] Alternatively, enforcement through military means - Congress hasn't authorized the use of force against dissenting states since the 1860s, but the threat is always there. Or paramilitary means, where an armed federal law enforcement group seizes control of state installations that aren't aligned with aspects of federal law. The DEA and ATF have a blueprint to follow here. Or financial means, where Congress orders federally-regulated banks not to engage with customers that don't respect its ID policies. There are other levers to pull, too. It's not that the States don't have any power, but in practice they are allowed the powers that the federal government chooses not to centralise - the opposite of how it works in theory, where the federal government governs only to the extent the States allow. [0] https://en.wikipedia.org/wiki/National_Minimum_Drinking_Age_... |