On Monday, in the city of Highland Park, Ill., a deranged goblin of a man opened fire on a July 4 parade, killing seven innocent people and wounding three dozen others. After an intense search, the culprit was apprehended and taken into custody. Yet again, a mass shooting has sullied America.

And, yet again, it is unclear what lawmakers can do to prevent the next one. Just weeks ago, the Senate passed a gun-control bill that Chris Murphy described as “the most significant piece of anti-gun violence legislation in nearly 30 years.” Today, posturing as if nothing has been done recently, Democrats are asking for more. But what, exactly, does that mean? A red-flag law? Illinois already has one. A permitting system for the purchase and ownership of guns? Illinois has that, too. “Universal” background checks? That’s already Illinois law. What about “assault weapons” and “high-capacity” magazines? Highland Park has banned both since 2013. Concealed carry? That was prohibited at the parade under an Illinois law that renders it illegal to carry firearms at “any public gathering held pursuant to a license issued by any governmental body.” Straw purchasing? That’s already illegal, and, besides, the gun was obtained legally. Can the courts be blamed, perhaps? They cannot. In 2015, the Seventh Circuit upheld Highland Park’s ban on “assault weapons” and “high-capacity” magazines, and the Supreme Court then declined to take up the case. As for Heller, McDonald, and Bruen — thus far, nothing that has flowed from them even intersected with this case.