[Lonesome in Massachussets]

Could he then federalize law enforcement?

Nope. The Constitution grants great autonomy to the several states. Unfortunately, Congress granted "home rule" to the District of Columbia, and what we got was:

on Pennsylvania Avenue

As H.L. Mencken noted, democracy is the theory that the people should get what they want [vote for] good and hard. New Yorkers are getting "our democracy" good and hard.

[skepsel]

The Constitution doesn’t grant autonomy to the states.

The Constitution delegates enumerated powers and only those powers to the federal government.

See the 10th Amendment.

“The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.”