That success is to be followed in 2019 by a ban on the use of lead-based ammunition throughout California. Other states have partial controls on lead ammo, but California is the first to enact such a sweeping environmental protection in the face of the powerful gun lobby.

In contrast, the Trump administration, beholden to the N.R.A., quickly overturned a regulation the Obama administration had issued that would have banned lead ammunition and fishing tackle in federal wildlife refuges.

Even when it comes to measures that can harm humans, Republican representatives tend to be equally servile toward the gun lobby. In the House, they are selling what amounts to a marketing favor for the gun industry, proposing to repeal controls on the sale of gun silencers to civilians. Silencer controls were enacted as a public safety precaution in the gangland rat-a-tat of the 1930s, when law enforcement officials wanted to make it harder for killers to escape detection. The nation at that time also cracked down on easy civilian access to machine guns and hand grenades.

Sponsors are intent on making silencers more available to firearm enthusiasts as vanity “quiet gun” products to protect a shooter’s hearing, despite warnings that readily available silencers pose a heightened threat to public health and safety. In the “active shooter” era of modern America, police departments in dozens of cities and towns have been using new technology to track the sound and location of gunfire so police officers can quickly be deployed to trouble spots.

The proposal is expected to be voted on in the coming weeks as part of an omnibus “sportsmen’s heritage” bill. The measure would also make it more difficult for federal regulators to control armor-piercing bullets — a particular threat to police officers wearing bullet-resistant vests, far from the hunting grounds of sportsmen.