Few things are more frustrating to lawful gun owners than politicians trying to fund one government program or another by placing additional taxes on them, even though they played no hand whatsoever in causing the problem being addressed.

Such is the case in Colorado where a ballot initiative would place an additional 6.5% excise tax on the retail sale of firearms, firearm parts and ammunition to fund domestic violence programs in the state.

According to a report in the Greeley Tribune, Colorado domestic violence services received 15,000 calls in a single day from victims requesting services. And next month voters will be voting whether or not to approve Proposition KK, which would fund those programs on the backs of gun and ammo purchasers.

If the ballot initiative passes, crime victim services, like district attorney’s offices, law enforcement and nonprofits, will receive most of the revenue—about $30 million—through grants to provide on-site crisis response, counseling, legal advocacy and emergency financial assistance. And while no gun owner would argue that those services aren’t important, it’s simply unfair to fund those programs by overtaxing gun owners.

Firearms and ammunition are already subject to an 11% federal excise tax through the Pittman-Robertson Act—of which the bulk goes to state wildlife agencies for conservation projects—along with a variety of other state and local taxes and fees. California is the only other state to have enacted a similar tax, with an additional 11% tax levied on firearms, gun parts and ammunition there.

The ballot initiative in Colorado is nothing more than what some would call a “sin tax” like that placed on items like tobacco products and alcoholic beverages. However, in this case, the only supposed “sin” being committed by Colorado gun owners is practicing their Second Amendment-protected right to keep and bear arms.

Some firearms retailers are speaking out against the tax, which they see as an attack on the right to keep and bear arms.

“It’s just another attack against the Second Amendment and a selected group of people,” Tim Brough, owner of Ault Ammo Depot, Rocky Mountain Shooters Supply in Fort Collins, told the Tribune. “It’s not like we’re taxing the whole population to solve a whole population’s problem. We’re taxing a small portion of the population to solve an issue.”

Along with being unjust, it’s likely the proposed Colorado tax is also unconstitutional under the 2022 Bruen ruling. And the Firearms Policy Coalition (FPC), National Rifle Association (NRA), Second Amendment Foundation (SAF) and California Rifle & Pistol Association (CRPA) have filed a lawsuit on the behalf of two individuals in the Golden State who were forced to pay the extra tax in an effort to get that state’s law struck down by the courts.

In the lawsuit, titled Jaymes v. Maduros, plaintiffs argue that the tax unconstitutionally targets gun owners for political purposes.

“Here, California effectively seeks the power to destroy the exercise of a constitutional right by singling it out for special taxation,” the complaint reads. “If this tax is permitted, there is nothing stopping California from imposing a 50% or even 100% tax on a constitutional right it disfavors—whether it be the right to keep and bear arms, the right to free exercise of religion or any other right.”

If the Colorado ballot initiative passes, it’s likely pro-gun groups will also be taking that tax scheme to court in the near future.