Groups like the National Rifle Association have long insisted that government should enforce existing gun laws rather than pass new ones. A bipartisan group of mayors from 450 cities, including some in Hampton Roads, is urging the Obama administration to heed that advice.

Mayors Against Illegal Guns, led by New York City's Michael Bloomberg and Boston's Thomas M. Menino, recently presented 40 gun-related recommendations to the White House and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The group - whose members include mayors from Norfolk, Virginia Beach, Portsmouth, Newport News and other Virginia cities - hasn't released the document, but The Washington Post obtained a copy and reported that it focuses on bolstering ATF resources and expanding enforcement of existing laws.

Among other things, the group calls for:

• Aggressive prosecution of people who fail background checks while trying to buy guns. The FBI referred almost 68,000 cases in 2005, but prosecutors pursued only 135.
• Giving the ATF $53 million to hire more field agents to inspect dealers more frequently. Right now, the report says, the agency is falling far short of its goal of checking dealers once every three years.
• Requiring manufacturers to hide a second serial number on guns because criminals often file off visible numbers.

So far, it appears the most controversial idea involves gun shows. The mayors want the ATF to conduct undercover investigations to ensure dealers are running background checks. The agency lacks a formal enforcement program.

Monitoring compliance is a reasonable idea, but gun groups have been engaged in a bitter fight with the mayors over gun show regulations. The NRA encourages its members to pressure mayors to drop out of Mayors Against Illegal Guns, chiefly over this issue.

Last week Mayor Bloomberg announced the results of an investigation of gun shows in Nevada, Ohio and Tennessee . He said investigators posing as buyers obtained guns illegally in almost three out of four instances.

Besides stricter enforcement of existing laws, the mayors have repeatedly called on Congress to require everyone selling guns at shows to conduct background checks.

Licensed dealers must run checks to screen out felons and others who aren't allowed to acquire firearms. But, according to Virginia State Police estimates, 22 to 35 percent of people selling guns at shows are private sellers who can choose whether to run checks - and often don't.

It's unlikely the NRA will ever fully agree with the mayors, but they should look for compromises that involve enforcing existing laws.

In the absence of a compromise, however, the Obama administration should press ahead with more rigorous enforcement and closing the gun-show loophole. The goal isn't to making gun groups happy. It's to make it as difficult as possible for criminals to get guns.