President Trump's history is all over the place when it comes to the Second Amendment and gun control.

Luckily, he has so far defended the Second Amendment as president, with the notable exception of his foolish, arguably illegal bump-stock ban, which would ban a popular firearm accessory via executive fiat.

So too, on the issue of background checks, Trump’s stance has been far from clear. He’s both opposed and vocally supported so-called “universal background checks” in the past. Yet with Attorney General William Barr meeting with congressional Republicans to push a gun control bill expanding background checks to private gun sales, it’s more important now than ever that Trump does not cave — and rejects background check expansion as the useless virtue-signal it is.

For one, the vast majority of gun sales already go through a background check. Current law requires any federally-licensed firearm vendor to run a background check before completing a sale. This is why almost 90% of firearm sales involve a background check already.

The tiny minority of gun transfers that don’t require background checks are person-to-personal sales, or private sales. In many states (and for all interstate sales) background checks are also already required. But whether you want such a rule in your state or not, required background checks will not stop mass shootings.

So how did we get here, if a desire to prevent mass shootings is what drove this proposal in the first place?

Many mass shooters, such as the Las Vegas shooter, pass background checks because they have no criminal or psychological history that would come up during a check. For other determined killers unable to pass a background check, they tend to obtain guns illegally — which can include having a friend or family member purchase it for them.

Basically, cries for “universal background checks” are part of the broader movement to “do something” in response to mass shootings, even if that something is just a virtue signal that won’t stop tragedies. Still, one might think: What’s the harm? Expanding background checks might not stop mass shootings, but an average person can be forgiven for thinking it’s a reasonable enough, harmless proposal nonetheless.

Here's the issue: Democrats are hell-bent on keeping long-term records of gun purchases, and law-abiding gun-owners value their privacy. Democrats' determination to track gun owners has blocked reform proposals in the past, and it will probably continue to do so. Anyone who values the preservation of gun rights has to oppose the creation of an effective gun registry — especially with Beto O’Rourke literally saying “yes, we’re taking your guns,” and receiving enthusiastic cheers from Democratic audiences. Government tracking of guns, after all, is a necessary precursor to mass confiscation.

Trump is surely feeling the heat on gun control, and exploring possible solutions. But he must not betray the Constitution and prudent policy just to cave to useless proposals, media fearmongering, and the political exploitation of tragedy.