Though the Constitution doesn’t say Washington has immigration authority, the Court derives it from the natural right of self-defense that undergirds the sovereign power of border security. But Washington won’t secure the border. Texas, which is supposed to be dually sovereign in our federalist system, is desperate to secure its border, but Washington won’t allow the border to be secured … notwithstanding that the duty to provide such security is Washington’s only legitimate claim to immigration-enforcement power.

As was bound to happen, the inference of a federal authority gradually became federal domination — the judicially endorsed power to preempt state law. For the states, this was a manageable arrangement as long as we were clear on what federal law is. That is, the law for these purposes is the corpus of statutory immigration law enacted by Congress. Congressional law as written is duly protective of state security and calls for the detention and removal of illegal aliens; state action was not preempted as long as it was consistent with this federal law. Thus, state enforcement supplemented federal enforcement, providing security.

The Obama/Biden administration, however, had a different theory. It contended that preemption means states are bound not merely by federal law but also by federal policy — i.e., the manner in which the executive branch chooses to enforce the laws. That, of course, includes the exercise of federal discretion not to enforce the laws, if that is the president’s preference. The Supreme Court bought that argument.