For all the talk about a possible breakthrough on background checks for gun buyers, it would be only a minor success if military-type assault weapons remain on the market.

Their continued availability since expiration of the ban enacted by California Sen. Dianne Feinstein in 1994 makes a mockery of any lesser reform, leaving the majority Republicans in the Senate still captive of the National Rifle Association.

The NRA’s successful campaign putting assault weapons back in the hands of Americans in 2004, with no sane or justifiable argument for doing so, should be the real objective of gun-control advocates, especially in the current era of spreading domestic terrorism.

The recent surfacing of a white supremacy “manifesto” allegedly issued by the young killer of innocents in El Paso, Texas, underscores the scope of today’s peril in such rapid-firing devices of death employed by its adherents.

Former Vice President Joe Biden, now seeking the 2020 Democratic presidential nomination, seized the issue Sunday in a New York Times op-ed, calling for the ban’s reinstatement along with another on sale of high-capacity bullet rounds.

“Republican leaders,” Biden wrote, “try to prevent action and parrot NBA messaging, as Donald Trump did last week when he said, ‘Mental illness and hatred pulls the trigger, not the gun.’

“This is the same president,” Biden continued, “who during his first year in office repealed a rule President Obama and I put in place to help keep guns out of people with certain mental illnesses. This is the same president who said after Charlottesville that there were ‘very fine people on both sides,’ and who continues to fan the flames of hate and white supremacy. We can’t trust his diagnosis.”

Biden also tweeted that he and Feinstein “led the successful effort to ban assault weapons and high-capacity magazines. It worked. It saved lives.”

As president, he said, he will take on the NRA again and make the ban “even stronger” this time.

Biden, who was chairman of the Senate Judiciary Committee when the assault weapons ban was enacted in 1994, said it was “the last meaningful gun legislation we were able to get signed into law before the NRA and the gun manufacturers put the Republican Party in a headlock.” Biden claimed his efforts then to extend the ban past its 2004 expiration were thwarted by the gun lobby.

Other 2020 Democratic presidential aspirants quickly joined the call, including Sens. Elizabeth Warren of Massachusetts and Cory Booker of New Jersey, former Texas Rep. Beto O’Rourke, and Mayor Pete Buttigieg of South Bend, Ind. Some went farther than Biden, calling for licensing of gun buyers, inviting certain NRA rejection.

Biden is skeptical of licensing, telling CNN it “will not change whether or not people buy what weapons, what weapons they can buy, where they can use them, how they can store them.”

While some Democrats question whether the former vice president still has fortitude and firepower to take on Trump, he quickly identified one issue on which support for enhanced public safety should be indisputable.

Citing police data on the murderous killings by such weapons, Biden stated the obvious: “Shooters looking to inflict mass carnage choose assault weapons with high-capacity magazines holding more than ten rounds. They choose them because they want to kill as many people as possible without having to stop and reload.” To have to spell that out would be laughable were not the consequences so grim.

As for the proposed background checks on guns buyers, a bill has already passed the House and is awaiting unexpected consideration in the Senate, where Republican Majority Leader Mitch McConnell has indicated he has no intention of calling it back into session, or of Trump asking him to do so.

Such is the state of political paralysis now inflicting the Grand Old Party under a president to gives lip service to background checks. but the back of his hand to any thought of enacting life-saving legislation.

Jules Witcover’s latest book is “The American Vice Presidency: From Irrelevance to Power,” published by Smithsonian Books.