Last week, President Trump, who hasn’t shown the slightest inclination to nudge his party toward passing universal background checks, or banning assault rifles or high-capacity magazines, made good on a promise to prohibit bump stocks.

Those are the appalling attachments, used in a 2017 Las Vegas massacre that took 59 lives, that enable semi-automatic rifles to fire continuously with a single trigger pull.

Under just-released administration guidelines, they’ll be verboten 90 days hence under the same federal law that prohibits machine guns.

To recap: It took 443 days to ban an accessory that enables legal assault rifles to be turned into even more industrially efficient murder machines capable of firing at a rate of up to 800 rounds a minute, reversing an idiotic decision by the Bureau of Alcohol, Tobacco, Firearms and Explosives that they didn’t amount to machine guns and therefore couldn’t be curbed without a new law.

And we have to pocket this as progress in a country in total thrall to the gun.