> There are cases spanning a century across several creative legislative attempts by the US Congress to create a de facto mandatory national identity system.
Then it should be easy to present one, preferably the most applicable one to modern proposals.
> This information is not difficult to find.
Its not easy to find the arguments of the people opposed to national ID, and its not easy to verify that the cases they cite are not about national IDs.
> All of them tried to workaround the fact that States can create mandatory identity systems but the Federal government cannot
None of the national ID debates have been about a mandatory ID (a mandatory-for-specific-purposes ID, yes, but the feds already issue a number of those.)
> (It is one of the reasons SSN cards go out of their way to assert they are not to be used as an ID.)
No, social security cards say that because they aren’t designed to validate identity, since all they contain is a name and a number and no way other than possession (which is extremely problematic) to associate that with a particular person.
> Past attempts included things like withholding tax disbursements to non-compliant States
[citation needed]
> but the US Supreme Court deemed that coercive and therefore illegal.
[citation needed]
> The Real ID Act is the latest attempt
Real ID is not a mandatory ID, but a required-for-enumerated purposes ID. The enumerated purposes are ones for which the federal government already establishes acceptable ID standards without any Constitutional challenge, under various Article I, Sec. 8 powers, Real ID is just a change to the standards. And all phases of it but for Phase 4 involving (notably) the mandated to use Real ID for commercial air travel have already gone into effect. Starting in 2014.
but it has been delayed for many years by State non-compliance and general unwillingness to share their identity databases with the Federal government.