"concurrent powers" Topic

I have been having a LONG back and forth with GROK about militia etc. You'd be interested but I don't know if I have the energy to copy and past a dozen questions and answers. But this is the last one I just did, because I routinely taught "concurrent powers" as any competent civics class presumably does. And GROK actually expanded my understanding of something I have taught for 50 years: I offered the gas tax as an example and then asked about who issues badges and guns.

GROK:

Gas tax is the clean concurrent-power slide: three treasuries, one commodity, one use (roads). Badge-and-gun authority is the slide that makes students see why federalism is not a layer cake.

The police power is reserved to the states. Almost every street arrest in the country is still a state officer enforcing state criminal law. The United States does not have a national gendarmerie. That is the starting point, and it is why a Cook County sheriff, a Chicago cop, a Texas State Guardsman, and an FBI agent can all be armed in the same intersection and not be the same kind of official.

Then concurrency and fragmentation pile on:

Federal officers exist because Congress has enumerated crimes, federal property, borders, and interstate systems. They do not replace the sheriff. They overlay him. When the overlay needs local bodies, the United States borrows them: FBI/DEA task forces, U.S. Marshals special deputation, 287(g) agreements. That is concurrent enforcement of different codes, sometimes by the same human wearing two hats.

The National Guard is the most baroque concurrent object in the system. One person, two enlistments, two commanders. State militia under the governor until a federal statute flips the switch. The Militia Clauses and the Army Clause sit next to each other and do not collapse into one.

State defense forces are Congress saying: you may keep extra troops the President cannot take. That is not "the states defied Washington." That is Washington authorizing a reserved state military so the Guard can leave and the state is not naked. Concurrent military power, deliberately split.

Sheriffs in many states are constitutional officers with a common-law posse power the legislature did not invent last year. Cities are creatures of the state. So you get the Jefferson County move: the county's elected officer papers every municipal cop so city limits stop being a legal wall. That is intra-state federalism—county versus city—using a medieval writ.

Illinois's "police district" is the legislature pre-solving the 1968 problem you remembered: adjoining municipalities in one county already share peace-officer power. Statute as concurrent jurisdiction among local sovereigns the state created.

None of that looks like the gas tax. Gasoline is the same molecule whoever stamps the gallon. A badge is a claim about which sovereign may use force, which code applies, who pays the judgment, and who can fire the person. Cross-deputization is the system admitting that the map of sovereignty is too fine-grained for a car chase.

For a class, the useful contrast is:

Tax concurrency is additive. Three governments can tax the same gallon; the driver just pays.
Force concurrency is exclusive in the moment. Only one set of rules for that trigger pull counts, even if three governments could have issued the gun. The law spends enormous effort deciding which set, then uses deputation, mutual aid, and dual status to fake a single chain of command when the map will not.
That is why "who can issue badges" is a better federalism example than it first appears. It is not that all three levels run the police. It is that the Constitution left the core of violence to the states, then built so many exceptions, dual offices, and borrowing mechanisms that a student can no longer point to one pyramid. The unorganized militia, the State Guard, the posse, and the task-force credential are all ways of moving armed people across those seams without admitting that the seams are still there.

For context, one of my (far too many) projects is a dystopian near-future novel. If we were to enter a new dark ages, via a Carrington event or such, what would local power structures and conflicts look like?