Just because you’re a lawyer it doesn’t mean you’re a good lawyer. Right now I’m having an argument with a lawyer in the comments of another blog about whether the states can sue the federal government over matters relating to the enforcement of state law. My understanding is that states have special standing WRT suing the federal government regarding matters of enforcing state law.
Among other things I believe that this means that states could impose a state payroll tax analogous to FICA that would apply to federal employees working in those states. I doubt that states could require the federal government to pay the employer side of such a tax but even on that I’m not sure. It would be an interesting test.