Attorney General William Barr is reportedly floating a proposal to expand background checks for gun buyers that is similar to an unsuccessful 2013 bill sponsored by Sens. Joe Manchin (D–W.Va.) and Patrick Toomey (R–Pa.). The proposal would require background checks for "all advertised commercial sales, including gun sales at gun shows."

Manchin and Toomey's Public Safety and Second Amendment Protection Act would have required that federally licensed firearm dealers, who are already required to conduct background checks, be involved in all sales at gun shows and all transfers resulting from online or print ads. It explicitly exempted transfers "between spouses,

between parents or spouses of parents and their children or spouses of their children, between siblings or spouses of siblings, or between grandparents or spouses of grandparents and their grandchildren or spouses of their grandchildren, or between aunts or uncles or their spouses and their nieces or nephews or their spouses, or between first cousins."

Barr's proposal would do pretty much the same thing, but it also would authorize licenses for "transfer agents" to help gun owners comply with the background check requirement. The idea, presumably, is that the new category of licensees would make compliance easier by providing an alternative to firearm dealers.

This proposal is less sweeping than the Bipartisan Background Checks Act of 2019, which the House of Representatives approved last February. That bill, which was supported by 232 Democrats but only eight Republicans, would ban almost all gun transfers by people who are not licensed dealers. It applies to any sale, whether or not it happens at a gun show and whether or not the firearm was advertised.

The House bill makes an exception for "a transfer that is a loan or bona fide gift between spouses, between domestic partners, between parents and their children, including step-parents and their step-children, between siblings, between aunts or uncles and their nieces or nephews, or between grandparents and their grandchildren." If money changes hands, in other words, a background check would be required even for transfers between relatives.

Both proposals share the same problems as any other effort to expand the reach of background checks. First, the categories of prohibited buyers are irrationally and unfairly broad, encompassing millions of people who have never shown any violent tendencies, including cannabis consumers, unauthorized U.S. residents, people who have been convicted of nonviolent felonies, and anyone who has ever undergone mandatory psychiatric treatment because he was deemed suicidal.

Second, background checks are not an effective way to prevent mass shootings, since the vast majority of people who commit those crimes do not have disqualifying criminal or psychiatric records. Third, background checks, even if they are notionally "universal," can be easily evaded by ordinary criminals, who can obtain weapons through straw buyers or the black market. Fourth, voluntary compliance is apt to be the exception rather than the rule, and enforcement will be difficult, if not impossible.

Since the Manchin-Toomey approach applies only to relatively conspicuous sales, enforcement would be easier, but only because unadvertised private sales would be exempt. The House bill would be mostly aspirational and symbolic, since the government has no way of knowing when guns change hands in private transactions if the sales are not advertised and do not happen at gun shows.

In a study published last year, researchers looked at what happened after Colorado, Delaware, and Washington expanded their background check requirements. They reported that "background check rates increased in Delaware, by 22%–34% depending on the type of firearm," but "no overall changes were observed in Washington and Colorado." It is hard to see how the federal government can do any better, since it does not know who owns which guns and cannot possibly monitor unrecorded private transfers.

After the mass shootings in El Paso, Texas, and Dayton, Ohio, last month, President Donald Trump signaled his support for expanded background checks. "Serious discussions are taking place between House and Senate leadership on meaningful Background Checks," he said in an August 9 tweet. "I have also been speaking to the NRA, and others, so that their very strong views can be fully represented and respected. Guns should not be placed in the hands of mentally ill or deranged people. I am the biggest Second Amendment person there is, but we all must work together for the good and safety of our Country. Common sense things can be done that are good for everyone!"

The White House, however, has not accepted ownership of Barr's idea, and most Republicans in the Senate will not support a background check bill unless Trump says he is prepared to sign it. Politico reports that "a senator who met with Barr said the attorney general made clear he had authorization from the White House." That seemed to be news to the White House. Presidential spokesman Hogan Gidley told Politico "the president has not signed off on anything yet but has been clear he wants meaningful solutions that actually protect the American people and could potentially prevent these tragedies from ever happening again."