First up should be criminalizing the equipment Paddock used to turn military-style arms into more hellish killing machines.

AU.S. Congress that did nothing after an assault-weapon-wielding maniac killed 20 children in a Connecticut elementary school, that did nothing after another armed-to-the-teeth madman cut down 49 revelers in an Orlando nightclub, now may outdo its own ineptitude after the murder of at least 58 concertgoers in Las Vegas.

President Trump has opened the door a fraction of a crack to revisiting firearm safety, suggesting Tuesday that the country will “be talking about gun laws as time goes by.”

But far too much time has already gone by: 1,755 days since the killings at Sandy Hook Elementary, 4,769 days since the federal assault weapons ban expired.

First on the list is a measure so simple and obvious it can be passed today: criminalizing the equipment, now cheap and legal, that Stephen Paddock used to turn two military-style assault weapons into even more hellish, fully automatic, nine-bullet-a-second killing machines.

Under federal law, fully automatic weapons are tightly regulated. That’s because, in 1986, when Ronald Reagan was President, Congress banned the transfer or sale to civilians of machine guns, and required the few hundred thousand already in circulation to be registered with the feds.

The statute validated a principle that all sane conservatives understand: The Second Amendment right to bear arms is not absolute. It does not safeguard the freedom of civilians to wield the deadliest weapons.

Which is also why assault rifles, which fire with a power utterly unnecessary for hunting or self-defense, were banned for a decade, starting in 1994.

When those prohibitions were in effect, the nation suffered dramatically fewer mass shootings. Since the ban expired in 2004, massacres have become soul-numbingly common.

And now, with the complete complicity of Congress, the lapse has been weaponized to effectively negate the 30-year-old machine gun ban as well.

For all assault weapons’ awful lethality, they’re semiautomatic, meaning their triggers must be pulled once per round. That changes with the aid of a simple add-on known as a “bump stock,” which lets a gun fire continuously until the magazine is empty.

They are cheap. They’re legal — approved by the Bureau of Alcohol, Tobacco and Firearms. They’re in stock now. We just found one online for $169.99. Free shipping!

Paddock had two such devices in his hotel room.

If members of Congress and President had true spine, they would push — now — to re-ban assault rifles. And the high-capacity magazines that let people fire dozens upon dozens of times without reloading. And ensure universal background checks. They will surely cave on those measures. But if after the horror of Las Vegas they prove unable even to ban the devices that turn semiautomatics into bullet-spraying machine guns, they will reveal themselves to be cowards more contemptible than even hardened cynics took them for.