LIKE REVOLUTIONARIES run amok, the gun control movement has started to turn on its own.

Late last month, Virginia Gov. Terry McAuliffe (D) scrapped an undeniably good deal for gun control advocates: an order, issued by the state’s attorney general, ending the commonwealth’s policy of recognizing concealed-carry permits from 25 states with lax standards. In return, Mr. McAuliffe got something better: a concession from the pro-gun lobby that will allow Virginia to criminalize gun possession by the nearly 5,000 domestic abusers smacked with protective orders annually.

Legislation to do just that has failed repeatedly in Richmond’s Republican-dominated legislature since at least 1997. Yet rather than being hailed for achieving what pro-gun-control lawmakers had been unable to attain for nearly two decades, Mr. McAuliffe has been vilified by gun safety advocates, including Everytown for Gun Safety, Michael Bloomberg’s deep-pocketed gun safety group, which has launched a muddle-headed social media and advertising campaign against him.

Mr. McAuliffe is a weapons safety advocate who made gun control bills the centerpiece of his legislative agenda last year, to no avail. His deal, reached in negotiations with the National Rifle Association and its allies, isn’t perfect. But cold-eyed assessment suggests that Mr. McAuliffe got the better bargain.

According to state statistics, 112 Virginians were killed in domestic violence incidents in 2014. In six cases, the suspect was under a two-year domestic violence protective order, and the victims, killed with firearms, were the ones who had sought that order.

Under Mr. McAuliffe’s deal, it is precisely those domestic abusers — a class of individuals adjudged to pose a credible threat of violence — who would be ordered to forfeit their weapons for the duration of the two-year, renewable protective order. It’s unknown how many gun owners were among the 4,800 Virginians hit with protective orders in 2014, but it could be a good chunk of them.

By contrast, the evidence is scant that out-of-state concealed-carry permit holders pose an equivalent threat. True, some Virginians barred from obtaining permits in the commonwealth may be able to obtain one from a state with more lenient standards, which Virginia would have to recognize. It’s doubtful that will be widespread.

Gun control advocates, including Everytown’s chief, John Feinblatt, are disingenuous. They suggest Mr. McAuliffe, without making concessions, could have signed legislation cracking down on gun-owning domestic abusers. In fact, GOP lawmakers in Richmond have killed such bills for years, and there was no sign they were relaxing their opposition.

Granted, problems remain. In order to enforce the requirement that abusers forfeit their weapons, the state will rely mainly on their protective-order-seeking partners for verification and reporting noncompliance to the police. Nonetheless, the state will wield a big stick: the threat of a felony conviction, and up to five years in prison, for violations.

Mr. McAuliffe has notched a victory for gun control. What a shame the advocates for that position are blind to it.