A year ago, Representative Thomas Massie of Kentucky posted a Christmas photo on Twitter. In it, Mr. Massie, his wife and five children pose in front of their ornament-bedecked tree. Each person is wearing a big grin and holding an assault weapon. “Merry Christmas! ps. Santa, please bring ammo,” Mr. Massie wrote on Twitter.

The photo was posted on Dec. 4, just four days after a mass shooting at a school in Oxford, Mich., that left four students dead and seven other people injured.

The grotesque timing led many Democrats and several Republicans to criticize Mr. Massie for sharing the photo. Others lauded it and nearly 80,000 people liked his tweet. “That’s my kind of Christmas card!” wrote Representative Lauren Boebert of Colorado, who then posted a photo of her four sons brandishing similar weapons.

These weapons, lightweight and endlessly customizable, aren’t often used in the way their devotees imagine — to defend themselves and their families. (In a recent comprehensive survey, only 13% of all defensive use of guns involved any type of rifle.) Nevertheless, in the 18 years since the end of the federal assault weapons ban, the country has been flooded with an estimated 25 million AR-15-style semiautomatic rifles, making them one of the most popular in the United States. When used in mass shootings, the AR-15 makes those acts of violence far more deadly. It has become the gun of choice for mass killers, from Las Vegas to Uvalde, Sandy Hook to Buffalo.

The AR-15 has also become a potent talisman for right-wing politicians and many of their voters. That’s a particularly disturbing trend at a time when violent political rhetoric and actual political violence in the United States are rising.

Addressing violent right-wing extremism is a challenge on many fronts: This board has argued for stronger enforcement of state anti-militia laws, better tracking of extremists in law enforcement and the military, and stronger international cooperation to tackle it as a transnational issue. Most important, there is a civil war raging inside the Republican Party between those who support democracy and peaceful politics and those who support far-right extremism. That conflict has repercussions for all of us, and the fetishization of guns is a pervasive part of it.

The prominence of guns in campaign ads is a good barometer of their political potency. Democrats have sometimes used guns in ads — in 2010, Joe Manchin of West Virginia, running for the Senate, shot a hole through a copy of the cap-and-trade climate bill with a single-shot hunting rifle. Since then, guns have all but disappeared from Democratic messaging. But in the most recent midterm elections, Republican politicians ran more than 100 ads featuring guns and more than a dozen that featured semiautomatic military-style rifles.

In one of the most violent of those ads, Eric Greitens, a Republican candidate for Senate in Missouri and a former Navy SEAL, kicks in the door of a house and barges in with a group of men dressed in tactical gear and holding assault rifles. Mr. Greitens boasts that the group is hunting RINOs — a derogatory term for ‘Republicans in name only’. The ad continues, “Get a RINO hunting permit. There’s no bagging limit, no tagging limit, and it doesn’t expire until we save our country.”

Twitter flagged the ad, Facebook banned it for violating its terms of service, and Mr. Greitens lost his race for office. He may have been playacting in the ad, but many other heavily armed people with far-right political views are not. Openly carried assault rifles have become an all too common feature of political events around the country and are having a chilling effect on the exercise of political speech.

This intimidating display of weaponry isn’t a bipartisan phenomenon: A recent New York Times analysis examined more than 700 demonstrations where people openly carrying guns showed up. At about 77% of the protests, those who were armed “represented right-wing views, such as opposition to L.G.B.T.Q. rights and abortion access, hostility to racial justice rallies and support for former President Donald J. Trump’s lie of winning the 2020 election.”

As we’ve seen at libraries that host drag queen book readings, Juneteenth celebrations and Pride marches, the Second Amendment’s right to bear arms is fast running up against the First Amendment’s right to peaceably assemble. Securing that right, and addressing political violence in general, requires addressing the armed intimidation that has become commonplace in public places and the gun culture that makes it possible.

A growing number of American civilians have an unhealthy obsession with ‘tactical culture’ and rifles like the AR-15. It’s a fringe movement among the 81 million American gun owners, but it is one of several alarming trends that have coincided with the increase in political violence in this country, along with the spread of far-right extremist groups, an explosion of anti-government sentiment and the embrace of deranged conspiracy theories by many Republican politicians. Understanding how these currents feed one another is crucial to understanding and reversing political violence and right-wing extremism.

The American gun industry has reaped an estimated $1 billion in sales over the past decade from AR-15-style guns, and it has done so by using and cultivating their status as near mythical emblems of power, hyper-patriotism and manhood. Earlier this year, an investigation by the House Committee on Oversight and Reform found that the gun industry explicitly markets its products by touting their military pedigree and making “covert references to violent white supremacists like the Boogaloo Boys.” These tactics “prey on young men’s insecurities by claiming their weapons will put them ‘at the top of the testosterone food chain.’”

This marketing and those sales come at a significant cost to America’s social fabric.

In his recent book “Gunfight: My Battle Against the Industry That Radicalized America,” Ryan Busse, a former firearms company executive, described attending a Black Lives Matter rally with his son in Montana in 2020. At the rally, dozens of armed men, some of them wearing insignia from two paramilitary groups – the 3 Percenters and the Oath Keepers – appeared, carrying assault rifles. After one of the armed men assaulted his 12-year-old son, Mr. Busse had his epiphany.

“For years prior to this protest, advertising executives in the gun industry had been encouraging the ‘tactical lifestyle,’” Mr. Busse wrote. The gun industry created a culture that “glorified weapons of war and encouraged followers to ‘own the libs.’”

The formula is a simple one: More rage, more fear, more gun sales.

A portion of those proceeds are then funneled back into politics through millions of dollars in direct contributions, lobbying and spending on outside groups, most often in support of Republicans… OpenSecrets reported…“From 1989 to 2022, gun rights groups contributed $50.5 million to federal candidates and party committees,” the group found. “Of that, 99% of direct contributions went to Republicans.”

This editorial was first published in The New York Times on December 10 and was a part of the Associated Press’ weekly editorial roundup.