An old rule of thumb holds that when someone says it’s not about the money, it’s really about the money.

But there are exceptions to almost every rule. The National Rifle Association is a case in point.

In the wake of the horror in Las Vegas this week, countless politicians, journalists and commentators are insisting that the National Rifle Association has a “stranglehold” on the Republican Party. Hillary Clinton claimed that the GOP-controlled Congress simply does “whatever they are told to do” by the NRA and the gun lobby.

The Washington Post and New York Times laid out splashy reports chronicling how much money the NRA has given to Republican congressmen. “Since 1998, the National Rifle Association has donated $3,533,294 to current members of Congress,” the Post reported in 2016.

The New York Times listed total NRA donations to certain GOP politicians alongside their statements offering condolences and prayers for the victims in Las Vegas. And the op-ed pages have been suffused with claims that the NRA has bought Republicans with blood money, stifling the popular will and thwarting democracy in the process.

There’s just one problem: It’s not true.

Oh, it’s certainly the case that the NRA and related groups have given a good amount of money to Republican politicians (and quite a few Democrats) over the years. But in the grubby bazaar of politician-buying, the NRA is a bit player.

Consider that $3.5 million in donations over nearly 20 years the Washington Post made such a fuss about. According to Opensecrets.org, the legal profession contributed $207 million to politicians in 2016 alone. Fahr LLC, the outfit that oversees the political and philanthropic efforts of billionaire anti-global-warming activist Ton Steyer, gave $90 million (all to Democrats) in 2016.

In terms of lobbying and political contributions, the NRA and the gun industry generally spend next to nothing compared with the big players.

According to OpenSecrets, the NRA spent $1.1 million on contributions in 2016 and $3 million on lobbying. The food and beverage industry has spent $14 million on lobbying in 2017 alone. Alphabet, Google’s parent company, spent $9 million on contributions in 2016.

In fairness, NRA-related outside PACs do bundle a good deal more cash, but it’s still a fraction of what big labor and the trial lawyers pony up. All NRA-related outside expenditures in 2016 added up to about $54 million. A single liberal super PAC, Priorities USA, spent $133 million.

Some people, even when they know these numbers, still can’t let go of the idea that opposition to gun control is bought and paid for.

Tim Mullaney, a writer for Marketwatch, wrote a richly detailed essay in which he chronicled just how minuscule the NRA’s financial support is — and how small the entire gun industry is — and yet he still concluded it has to be about the money. He writes that “it’s shocking when you realize that it costs only $2,500 per each of the 22,000 or so gun-murder victims of the last election cycle to make Congress cower and refuse to tighten gun rules.”

Part of the problem, I think, is that people who hate guns and gun rights cannot believe that people disagree with them in good faith. There must be evil motives, chiefly greed, that explain everything.

The simple reality is that the NRA doesn’t need to spend a lot of money convincing politicians to protect gun rights. All it needs to do is spend a little money clarifying that a great many of those politicians’ constituents care deeply about gun rights.

If you don’t know anyone who has a gun, you live in a bubble.

Four out of 10 Americans have a gun in their household, according to a Pew Research Center survey. Seventy-three percent of gun owners say they can’t imagine not owning a gun. A quarter of gun owners say having a gun is very important to their overall identity.

This is why gun control is a great issue for Democratic fundraising — but an even better issue for Republican get-out-the-vote efforts. Politicians understand that.

Politicians may be craven (it’s often the safest assumption), but their priority is winning elections. Money-grubbing is a means to that end. And so is vote-grubbing. Maybe some politicians secretly favor stricter controls on guns. But what keeps them from pursuing such restrictions isn’t cash from the NRA; it’s votes from their passionate constituents.

In other words, don’t follow the money, follow the votes.

Twitter @JonahNRO