One of the things the Bruen decision laid down is the history, text, and tradition standard for gun laws. A measure has to be consistent with this standard in order to be ruled constitutional.

Rahimi muddied the waters more than a little bit by arguing that the analog doesn't have to be as close as many were thinking, which has created a lot of confusion, but the standard remains.

In short, there has to be some kind of historical analog that shows such restrictions were acceptable either at the time of the nation's founding or when the 14th Amendment incorporated the Bill of Rights and applied it to the states.

And Chicago is facing an uphill fight to keep people from exercising their Second Amendment rights on their mass transit system.

Posted at entries to some Chicago L train stations is an unmistakable emblem: a black handgun with a red slash through the middle, warning that firearms are not allowed on board.

On Wednesday, attorneys will go before a federal appellate panel to argue whether those placards should stay in place.

The US Court of Appeals for the Seventh Circuit is slated to review an Illinois law that prohibits concealed-carry permit holders from taking their guns on public transit. A federal district judge last year ruled in favor of four men who sued for the right to carry on Metra commuter trains and Chicago Transit Authority buses, prompting an appeal from the state attorney general and state’s attorneys for Cook and DuPage counties.

The underlying ruling is somewhat limited: Northern District of Illinois Judge Iain Johnston didn’t bar the state from broadly enforcing the law, and his order made clear he only found the statute unconstitutional as applied to the four plaintiffs.

But the appeal attracted amicus briefs from far and wide, a sign that advocates see it as a chance to clarify the Second Amendment legal landscape after recent seismic changes—most prominently the US Supreme Court’s finding in N.Y. State Rifle & Pistol Ass’n. v. Bruen that gun regulations must be consistent with the country’s “historical tradition.” Bruen, combined with a later holding on gun restrictions in United States v. Rahimi, has spurred federal courts to consider whether assault weapons bans, handgun licensing requirements, and other regulations have a historical analog.

If the appeals court agrees with the district judge in the Illinois matter, it could open the door to a broader challenge on behalf of concealed-carry holders across the state, said Erin Erhardt, litigation counsel at the National Rifle Association Institute for Legislative Action.

And let's be clear here, there's not really any history that supports this. While one might argue that there couldn't be from the time of the nation's founding because trains weren't really a thing, they were when the 14th Amendment was ratified. Trains were the most common way to travel long distances, really, and without some law suggesting guns weren't allowed, there is no analog.

Even with the broader net cast by Rahimi, I can't think of anything remotely close from either era.

As such, it just doesn't seem likely that Chicago's attorneys are going to be able to make that case. That will, as Erhardt notes, open the door for others to press their own challenges.

The truth of the matter, though, is that gun-free zone signs at mass transit stations don't do anything except discourage the law-abiding. Those who care nothing for the law will carry guns or other weapons as they please. It's kind of what criminals do. They don't figure they'll get caught, so they don't even think of it as a risk.

Meanwhile, those signs and the laws authorizing them turn people into potential victims just because some people don't trust us with our right to keep and bear arms while riding a train around town.

The history doesn't back them up.

That's a good thing.