A small-time K Street battle between hearing aid manufacturers on one side and electronics firms who want to make cheaper ones on the other has attracted the attention of a radical gun rights group, looking to take a shot at one of the bill’s backers.

A bipartisan group in in the Senate introduced a bill in March to make hearing aids more affordable by allowing them to be sold-over-the counter. Only a handful of manufacturers make hearing aids, and most state laws restrict the selling of hearing aids to licensed audiologists, giving them an effective monopoly.

After a huge markup by the manufacturer, the audiologists add another premium, bundling the cost of the device with the cost of their services.

As a result, hearing aids are out of reach for more than 80 percent of people with hearing impairment. So a market has sprung up for affordable sound amplification devices. They are not hearing aids, and users will struggle with them in noisy situations like restaurants, but they’re better than nothing.

The devices — they’re called personal sound amplification products (PSAPs) — can’t legally be advertised as treating hearing loss without FDA approval, but marketers of them push as close to the line as they can. They are popular with hunters, who use them to hear animals in the woods and also to compensate for rifle-related hearing loss.

The bill wouldn’t stop PSAPs from being sold the way they are now. But it would give sound companies like Massachusetts-based Bose access to a brand new market, and drive down the cost of hearing aids for millions of hearing-impaired people.

The bill has the support of powerful Republicans in both the House and Senate. But it also has a powerful Democratic supporter: Sen. Elizabeth Warren of Massachusetts.

That — and, apparently, that alone — is enough to have the bill in the crosshairs of a group of ultra-conservative gun rights advocates — the Gun Owners of America — and their political allies.

The GOA says it has two beefs with Warren’s involvement: they don’t trust her, and they don’t want her to get a win.

Co-sponsored by more Senate Republicans than Democrats, and backed by the libertarian Niskanen Center, Warren’s bill is a rare example of truly bipartisan healthcare reform. Progressives back efforts to lower the cost of hearing aids, and conservatives can support the idea of ending a government-guaranteed monopoly and allowing competitive markets to set prices.

For the GOA, it’s an attack on hunting. The group circulated a letter earlier this month on Capitol Hill, claiming that the bill would allow the FDA to regulate sound amplification devices frequently used by hunters.

That isn’t true. Warren’s bill wouldn’t affect the sale of any PSAPs unless companies market them as a medical solution to hearing loss. So cheaper PSAPs, like the kind frequently used for hunting, would still be widely available, but upmarket hearing aids — customizable to your own type of hearing loss — would be far cheaper.

“In the past, anti-gun senators like Warren have used any pretext, however attenuated, to interfere with hunting and the exercise of Second Amendment rights,” the GOA letter reads. “And we can only interpret this legislative initiative to be the most recent of these.”

The letter singles out Warren for criticism without mentioning any of the bill’s conservative backers.

When asked by The Intercept why GOA neglected to criticize or even name the bill’s Republican co-sponsors, Mike Hammond, legislative counsel of GOA, said that the Republicans were really just working with her so they could claim a bipartisan legislative victory.

“My larger question is,” said Hammond, “at a time in which Warren in particular is sitting on everything that Republicans care about, why should they be intermediaries, pushing something she desperately wants, just for the sake of saying, well, we passed this bipartisan legislation?”

The bill has also triggered massive lobbying expenditures by both sides — hearing aid manufacturers and lobbying groups have spent more than $150,000 dollars trying to stop Warren’s bill, according to the Boston Globe. But audio device companies like Bose have also spent money in support of the bill, hoping to enter the market for over-the-counter hearings aids.

The bill has — or had — serious momentum, getting attached to a must-pass piece of legislation related to the FDA and coming in for praise from diverse quarters. But opponents hope yoking it to the culture wars at the last minute will make it too controversial for Republican leaders in the end.

Meanwhile, there are about 12,000 audiologists in the U.S. who make a significant portion of their income through the sale of hearing aids, and they’re worried about the future of their industry. Jodi Follweiler, who owns and runs JLF Hearing Aid Sales & Services in Kutztown, Pa., is a strong supporter of Warren, but is torn on the bill. “I get why she’s doing it, and if I weren’t in the industry I’d probably support it. But it’s going to kill me,” she told The Intercept. “The irony is it’ll be great for hunters, but they’re used to voting against their own interests, so this is nothing new for them.”

Ryan Grim contributed reporting. Disclosure: Follweiler is his uncle’s sister.