What we should focus on is curbing access to guns among people who present the greatest risk. An imperative first step is universal background checks to acquire a gun. New Harvard research suggests that about 40 percent of guns in America are acquired without a background check — which is just unconscionable.

Astonishingly, it’s perfectly legal even for people on the terrorism watch list to buy guns in the United States. More than 2,000 terrorism suspects did indeed purchase guns in the United States between 2004 and 2014, according to the Government Accountability Office and The Washington Post’s Wonkblog. Democrats have repeatedly proposed closing that loophole, but the National Rifle Association and its Republican allies have blocked those efforts, so it’s still legal.

While Republicans in Congress resist the most basic steps to curb gun access by violent offenders, the public is much more reasonable. Even among gun owners, 85 percent approve of universal background checks, according to a poll this year.

Likewise, an overwhelming share of gun owners support cracking down on firearms dealers who are careless or lose track of guns. Majorities of gun owners also favor banning people under 21 from having a handgun and requiring that guns be locked up at home.