Senior Senate Democrats bluntly acknowledged Tuesday that a proposed federal ban on assault weapons will not become law, bowing to the political calculus that only lesser gun control measures stand a chance of passing Congress, despite three months of emotional national debate since the Connecticut school massacre.

In separate remarks to reporters, Majority Leader Harry Reid, D-Nev., and Sen. Dianne Feinstein, D-Calif., both said they do not see Feinstein’s far-reaching proposal on assault weapons passing the Senate, let alone the Republican-led House, where opposition to the measure is even stronger.

“I very much regret it. I tried my best, but my best, I guess, wasn’t good enough,” Feinstein, a senior member of the Judiciary Committee, said of her bill (S 150), which would ban the future production of 157 specific kinds of guns, as well as ammunition magazines holding more than 10 rounds.

Although Feinstein refused to label her measure “dead”— “I don’t give up,” she said — she sounded an unusually pessimistic note about its chances after conferring with Reid, who informed her that he would not bring the bill to the floor as a stand-alone measure. The Judiciary Committee passed the assault weapons ban on a party line vote on March 14.

Instead, Feinstein said, her legislation will be offered as an amendment to a less ambitious gun control package that is likely to include a committee-passed crackdown on gun traffickers (S 54) and legislation that would provide more funding to improve school security (S 146). A third committee-passed measure, calling for background checks on most gun purchases (S 374), is still being negotiated among a bipartisan group of senators, but also could be included in the underlying gun legislation that reaches the floor.

Reid said he hopes to bring the package to the floor in early April, after the spring recess, and that he is still deciding which bill or bills would make up the base proposal. He said he is evaluating the bills that have passed through the Judiciary Committee and intends to settle on one or more that can attract the 60 votes that would be needed to open the debate.

But he said that Feinstein’s legislation would not be among them.

“Right now, her amendment — using the most optimistic numbers— has less than 40 votes. That’s not 60,” said Reid, who has personally declined to endorse the assault weapons ban and voted against its previous iteration in 1994. “I have to get something on the floor so we can have votes on that issue and the other issues that I’ve talked about, and that’s what I am going to try to do.”

Feinstein’s bill itself will be subject to two separate votes, both as amendments to the larger gun package, she said. The first would be a vote on the entire assault weapons bill, and the second would strip out the legislation’s ban on high-capacity ammunition magazines. She said Reid likely views the latter component as likelier to win passage.

Feinstein characterized her meeting with Reid not as a negotiation but more of a declaration from the majority leader.

“I made my argument, but that’s the way he feels,” she said.

‘I Can’t Fight the NRA’

She also pointed to the power of the National Rifle Association as one reason for the tough road her legislation has faced, even after one of the worst school shootings in American history.

“I can’t fight the NRA. The NRA spends unlimited sums, backed by the gun manufacturers — who are craven, in my view,” she said. “I don’t know what else to do, other than the best we can in drafting a bill, in asking for support and in enabling something to pass in the Senate. Now I could put a hold on the whole package, you know? But I’m not going to do that.”

While Feinstein and Reid both acknowledged the end of the road for the assault weapons ban, gun control advocates are making clear that they don’t want to see Senate leaders similarly give up on the universal background check legislation that the White House has made its top gun priority.

Mark Glaze, the director of Mayors Against Illegal Guns, cautioned Reid against excluding a background check proposal that has attracted much attention— as well as strong public support — but so far is lacking a single Republican co-sponsor.

“I know [Reid] is testing the waters about leaving the background check bill out,” Glaze said. But to exclude the proposal as part of the base legislation would be a “waste of an important public moment,” he said.

“I think it misreads the politics of the moment,” Glaze said. “The background check option has by far the best politics attached to it while being the biggest policy fix. If Congress can’t find a way to approve an effective background check bill when there is near unanimity among the American public, it’s hard to understand what they could do.”