After Sandy Hook, after twenty children were shot and killed at a place where they should have been safe from all harm, there was some optimism among supporters of gun control: perhaps now, finally, both Democrats and Republicans could see the light—and the suffering—and revive the assault-weapons ban. It was a futile hope.

Less than a week after Adam Lanza shot up an elementary school, it was already basically clear that an assault-weapons ban could not pass Congress—that it probably couldn’t even get through the Democratic-controlled Senate, never mind the House. So it was hardly a surprise when, three months later, Senate Majority Leader Harry Reid announced that the ban would be removed from a larger gun-control package that is making its way through the upper chamber and given a separate vote that it will not survive. The scale of the defeat suffered by the ban’s supporters, though, is shocking. This wasn’t a close call; it was a body blow.

On Tuesday, Reid told reporters that, “using the most optimistic numbers,” the ban sponsored by Senator Dianne Feinstein, a Democrat of California, will come to the floor with “less than forty” yes votes. If that’s true, it means that of the senators who were on the fence and might theoretically have been persuaded to support the legislation—there may have been as many as fifteen of them, and perhaps more—Feinstein and her allies lost almost every single one.

Those gun-control supporters who tend toward the glass-half-full side of things can reasonably view this as Feinstein et. al realizing that the real goal of the post-Newtown anti-gun push was a law making background checks universal—that the ban was just a sacrifice offered up to ease that law’s path through Congress—and letting any Democrats nervous about the backlash against a pro-ban vote off the hook.

There’s another way to interpret Reid’s vote count, though. Even after Tucson, and Aurora, and Sandy Hook, the N.R.A. won. Even with polls showing a majority of the country in favor of a ban and the President publicly behind it, more than a quarter of the Senate’s Democratic caucus would have voted against it, and there may not be any Senate Republicans who would have voted for it. Three months ago, there were pro-gun senators—including Reid—who were making noises about coming around on assault weapons. To a man, it appears, they have reconsidered.

All of that is, most likely, very bad news for those pushing for expanded background checks. In order to trade a ban for background checks, gun-control advocates probably needed to show that there was at least a slim chance a ban could become law. They’ve failed to do that. So now what reason do moderate Republicans—whose votes will be necessary in both the Senate and the House—have to buck their party and vote for background-check legislation that the N.R.A. strongly opposes? What reason do Democrats in battleground states and districts have to put their reëlection on the line? That it’s the right thing to do? That most people in the U.S. support it? These things have never been enough.

And indeed it does seem that the background-check proposal is in serious jeopardy. At some point in the near future, probably next month, Reid will bring a more tepid package of legislation to a vote. It will likely include increased penalties for straw purchasers—that is, people who buy guns for those who are not supposed to have them—and new money for school safety. It was also supposed to include background checks. Now, according to Reid, it may not. In fact, as the Times’s Jennifer Steinhauer notes, it’s entirely possible that by the time the Senate is done amending it, a bill that was supposed to be the culmination of months of work by gun-control advocates and an expression of the national anger over all these recent tragedies will end up as pro-gun legislation.

Photograph by T. J. Kirkpatrick/Getty.