Imagine the federal government telling you that you can’t exercise a constitutional right. Your neighbor takes a stand, challenges this prohibition, and wins. A federal court agrees that the government can’t enforce this law.
Now, let’s say you want to do exactly what your neighbor did, and you’re in the same judicial district where that prohibition was just lifted. The government, however, is still planning to use the same law and arguments against you.
You might think, reasonably, that since the government lost its case, that should mean you can proceed without any issues, right? Well, under the current Supreme Court rules, the federal government gets to try its luck again. In fact, they can do this every time someone wants to assert the same right under that same unconstitutional law.
Our organization, the Texas Public Policy Foundation’s Center for the American Future, is representing two Texans, David McCann and Kirk Launius, in a case that challenges this unusual privilege.
The crux of the issue is whether individuals can carry legally owned firearms when visiting a post office. Federal law, along with Postal Service regulations, forbids firearms on postal property, even for those who are legally carrying for self-defense, which is a recognized constitutional right.
Back in 2025, a group of plaintiffs took on these restrictions in the Northern District of Texas and won, with a federal judge ruling that the government could not enforce the prohibitions on lawful firearm possession at post offices.
Regardless of your thoughts on that specific firearms ruling, it reveals a larger procedural issue. As it stands, that ruling only protects the specific plaintiffs involved in that lawsuit. So, even though the Northern District of Texas found the restrictions unconstitutional, individuals in the same district still face those same restrictions.
McCann and Launius found themselves in this situation. We then filed another lawsuit for them in the same federal district, raising a broader question: how many times can the federal government keep litigating the same issue after losing?
Typically, our legal system does have an answer for this. The doctrine of collateral estoppel, or issue preclusion, is supposed to prevent a party from endlessly relitigating an issue already decided against it.
The idea is pretty simple: litigation should eventually come to an end. A losing party can’t keep bringing the same issue back to court hoping for a different outcome.
However, in 1984, the Supreme Court created a unique exception to this rule for the federal government.
In the case of United States v. Mendoza, the Court ruled that the federal government generally can’t face what is termed “nonmutual offensive collateral estoppel.” This means that someone not involved in the first case usually cannot use the government’s previous loss to stop it from tackling the same issue again with them.
The Court had some practical reasons for this exception. Since federal litigation happens across the country, it’s seen as important for legal questions to develop through the government’s defense in various courts. Additionally, the Court thought it wouldn’t be fair for the government to have to appeal every adverse ruling for fear that one loss would lock them into a nationwide precedent.
While those justifications might explain the Court’s reasoning, they come at a real cost: they let the federal government relitigate matters it has already lost, making it a continual challenge for Americans wanting to uphold recognized rights. Thus, even when judges rule against the government, it holds a kind of power over the populace.
Recent decisions, like the Supreme Court’s ruling in Trump v. CASA, exacerbate this issue. Unlike Mendoza, which was concerned with preventing repetitive litigation, CASA is about what happens after litigation. The Court ruled that typically, one judge can’t block a federal policy for the entire country. Instead, relief is usually limited to the parties who brought the suit, meaning one person can win while others still face the same government actions.
Our case seeks to clarify whether Mendoza should require such outcomes for everyone else in the same federal district.
McCann and Launius aren’t trying to enforce one district judge’s decision nationwide. They’re trying to uphold their rights in the same district court where the government had already lost on the same issue. Nevertheless, the district court found that under Mendoza, that fact didn’t matter, and they must go through the entire litigation process again.
We are currently appealing this decision to the U.S. Court of Appeals for the Fifth Circuit.
Since our cases were filed, things have become clearer. The government has dropped its appeal of the original ruling regarding post offices, leaving that decision intact. Moreover, the Trump administration’s Office of Legal Counsel has now ruled that those restrictions are unlawful.
So, the government lost its case, abandoned its appeal, and has now recognized that the regulatory prohibition violates the law. Yet, according to the district court’s interpretation of Mendoza, another citizen in the same district still can’t use that previous judgement to avoid relitigating the issue.
This situation doesn’t help uphold healthy disagreements among courts; rather, it creates chaos within the same court system.
And following CASA, this problem has implications that go far beyond this specific case. If judicial relief typically protects only those who sue, while Mendoza allows the federal government to readdress the same issue with every new plaintiff, it essentially means constitutional rights die at the government’s leisure, even within the same district.
This shouldn’t imply that one district judge can dictate federal law for everyone. Courts can still disagree, legal questions can evolve, and appellate courts can set binding precedents, as CASA outlined.
Yet, there’s a significant difference between letting various courts disagree and mandating the same court system to reevaluate the same issue every time a new citizen steps into the courthouse.
Mendoza claimed to protect the valid development of federal law. In a post-CASA context, it must not devolve into a rule of endless relitigation.
When the government loses, it should have options similar to other litigants: accept the ruling or appeal it.
It shouldn’t be granted an unlimited number of second chances.
