Umpqua Community College student John Parker Jr. didn’t think much about bringing his gun to campus last Thursday. An Air Force veteran and Oregon concealed weapon license holder, he had his handgun with him when the school went into lockdown during a mass shooting that left 10 people dead and eight more injured. The next day, Parker told MSNBC that he thought about trying to intervene, but ultimately decided not to, fearing he might interfere with a police response.

Parker’s story quickly took on outsized importance: He was carrying a gun on a campus that many commentators believed was a gun-free zone. While UCC prohibits possession of guns on campus, it makes exceptions for some students with written permission. A local NBC reporter followed up with Parker to see if he knew he’d violated school policy. “I don’t care what the policy is,” Parker said, adding that both the federal and Oregon constitution supplied him with all the justification he needed to carry a gun to school.

With his comments, Parker had unwittingly wandered into Oregon’s ongoing fight over the legality of guns on campus, which has largely played out in the courts. Schools there maintain they have the right to determine rules about guns on their grounds since they are obligated to protect the safety of their students and employees. But gun activists point to Oregon’s preemption law, which bars any administrative body below the state legislature from regulating firearms. In the resulting battle, Oregon colleges have scored a temporary victory — but would likely see their policies regulating guns on campus get overruled in court should they ever try to enforce them.

The legal wrangling began in 2009, when Jeffrey Maxell, an ex-marine and junior at Western Oregon University, was arrested for carrying a loaded gun on campus. At the time, the Oregon State Board of Higher Education had an administrative rule that banned all weapons at colleges and universities, but Maxwell, a concealed carry holder, argued that he had not violated any state law. With the help of the gun-rights advocacy group Oregon Firearms Federation, the charges were eventually dropped, but Western Oregon suspended Maxwell and required that he undergo a psychological evaluation. This led an affiliated group, the Oregon Firearms Education Foundation, to bring a suit challenging the Oregon education board’s administrative rule, claiming that it violated the Second Amendment as well as the state’s preemption statute. The OFEF suit got the rule struck down on the grounds of the preemption law, but it didn’t establish a constitutional right to carry guns on campus (Parker’s rationale for carrying at UCC notwithstanding).

In 2012, the Oregon University System put in place a new gun ban — but called it “policy.” It was a legal sleight of hand that the schools believed would allow them to skirt the preemption law. And it has, so far.

The tensions that can exist between a school’s priorities and state statutes are now surfacing in Michigan. Since 1990, Michigan has also preempted any jurisdiction below the state legislature from making its own gun laws; the University of Michigan, meanwhile, bars firearm possession anywhere on school property. Joshua Wade, a resident of Ann Arbor, sued the university in June over its ordinance. (Wade caused a major controversy in March of this year when he brought his weapon to his daughter’s choir performance at an Ann Arbor public high school.) Wade argues that as a concealed carry permit holder, he should be able to carry his guns on university grounds, including parking spaces and open areas.

There are five states that definitively allow guns on campus: Colorado, Idaho, Mississippi, Utah, and Wisconsin. Kansas and Texas passed laws this year to allow the practice in the future. As campus carry becomes a new cause celebre for gun activists, many may find success in the courts if they challenge school administrators on preemption grounds.

And that seems inevitable. At UCC, gun-carrying students seem to view policies limiting guns on campus with a grain of salt, if they acknowledge them at all. Parker didn’t know or care that he had to get that permission to have a gun on campus. Yahoo News found at least one other UCC student, Jeremy Smith, who also carries concealed while attending classes. “It’s not a gun free zone,” Smith said. A spokesperson for University of Oregon Campus Safety, Kelly McIver, says that school police can arrest people suspected of carrying on campus and penalize students or faculty with internal disciplinary measures.

But if Oregon gun rights activists connected with a student determined to carry on campus — a student like, say, John Parker Jr. — they would have a good chance of successfully challenging the rule. As Kevin Starrett, director of Oregon Firearms Federation, tells The Trace, “The fact of the matter is, a student brings a gun onto campus and the university threatens disciplinary action. We send in one of our lawyers, and the whole things goes away.” Tobin Klinger, a University of Oregon spokesman, couldn’t recall an instance where this actually happened.

“The school must figure that no one will challenge the rule,” UCLA law professor and Second Amendment expert Adam Winkler tells The Trace, referring to the Oregon policy at large. “Or, more likely, that it nonetheless serves the school community to have the ban in place until it is overturned.”