There are two different constitutional principles invoked in your post and only one is relevant to TK's post.

The first is based on the federal government using its spending power coercively (the highway money example). Basically, the federal government can pressure states to enact federal policies by either giving or withholding funds. BUT the pressure cannot become coercion. The obvious question is when does pressure become coercive? The answer to that is unclear and there is no clear rule to it. Regardless, this is not implicated in TK's post. The federal government is not witholding or giving money here. It is threatening to throw state officials in jail.

The second principle is the anti-commandeering principle (the case I linked to previously). This says that the federal government cannot force states or localities to enforce its laws for the federal government. The example is the federal government passing a law requiring state officials to process gun registrations. This was unconstitutional commandeering. To me, the federal government throwing state officials in jail unless they took steps to enforce a federal law (by notifying the federal officials) clearly falls over the line.

You did hit on a common critique of the anti-commandeering principle which is that there is no good way to distinguish permissible federal regulation on the states from impermissible federal commandeering of the states. You may have a point, but I am very confident that a court applying current law would find that this is commandeering.

[Post edited by BonsackHoo at 01/16/2018 7:57PM]