Allowing teachers to carry guns is a good idea. While anti-gunners may disagree, a lot of people don’t. However, it seems that even if states have the good sense to allow teachers to carry, the school districts themselves don’t.

At least, that’s true in some places.

Officials in rural states like South Dakota and Wyoming told President Donald Trump’s school safety commission on Tuesday that few school districts have taken advantage of state laws there to train and arm teachers.

The lack of participation comes despite a ringing endorsement from the president, who touted the idea of arming trained school staff after the shooting in Parkland, Fla., earlier this year that left 17 people dead.

South Dakota passed a law in 2013 creating the “School Sentinel“ program, becoming one of the first states with legislation explicitly allowing staff to carry guns in public schools in districts that choose to adopt the program. Teachers who want to become sentinels must go through 80 hours of training.

“We always thought — and the argument in the Legislature was — that it would be for those most rural schools, where law enforcement was an hour, half-hour away,” said Mike Milstead, sheriff of Minnehaha County in South Dakota.

As it turns out, one of the only sentinels in the state is stationed at a school in his county that already has a school resource officer, Milstead said.

So, what’s the deal?

Well, that’s a good question, but thanks to Politico, any potential school shooter in South Dakota knows at least one county to avoid.

The thing is, we don’t need every teacher armed. We don’t even need most teachers armed.

What we mainly need is the potential threat of armed teachers. That will generally be sufficient to dissuade most potential problems from ever happening. The not knowing if there’s an armed teacher means they factor that into their plans, and that may be enough.

When it’s not enough, that’s when we need good people with guns to meet the threat.

Unfortunately, when people talk about the horrors of armed teachers, they forget that we’re talking about responsible adults who generally already carry guns on a regular basis without incident. We’re not talking about issuing firearms with lesson planners here.

But when it is allowed, why doesn’t it happen?

Well, there are a number of potential reasons. One is, of course, teachers are more likely to have a political ideology that thinks of guns as bad things. Another is that when states require special training, that creates a barrier that many won’t want to fool around with. Especially if there’s a list of requirements that include everything from permission from your bosses–people who may not approve of firearms in the first place–to approval from a doctor.

Either way, teachers not taking up an opportunity doesn’t mean that opportunity shouldn’t exist. Instead, they should take a step back and try and find out just why people aren’t taking advantage of it.

Not that anti-gunners will ever comprehend that. They never do. Instead, they’ll pretend that it’s proof that teachers don’t want to be armed, as if that should mean that none should be armed.