"A fear has set in that if they vote for the bill they won't be re-elected. It's that plain, it's that simple," Feinstein said Wednesday to a crowd of 500 in San Francisco, according to The Associated Press. "My view is they shouldn't go up to the Senate if they are unwilling to stand up and vote."

Feinstein did not explicitly name which lawmakers were not supporting her bill because of reelection fears, but she mentioned Florida, Montana, Tennessee, and Wyoming as states where the NRA had been successful in applying pressure.

In April, Senate Majority Leader Harry ReidHarry Mason ReidDanny Tarkanian wins Nevada GOP congressional primary McConnell cements his standing in GOP history American people want serious legislators who collaborate across party lines MORE (D-Nev.) decided to remove an assault weapons ban from a package of gun measures he plans to bring to the Senate floor for a vote. Reid said the ban would have weighed down the entire package. But Reid did say Feinstein's assault weapons ban would get a vote as an amendment.

President Obama and some lawmakers have called for an assault weapons ban and a number of other gun control laws. Congress has sought to pass new legislation to prevent a repeat of the shooting massacre at Sandy Hook Elementary School in Newtown, Conn., that killed 20 children and six educators.

The NRA denied that it had threatened to fund opponents of lawmakers supporting the assault weapons ban.

"In spite of what Sen. Feinstein is trying to spin, to try and put the blame on the NRA, the real reason that there is lack of support for these bans is because we had a 10-year period where these bans were the law of the land, and during that 10-year period numerous studies were conducted that found these bans were ineffective at reducing crime," NRA spokesman Andrew Arulanandam said according to the Associated Press.

On Tuesday the NRA released its own proposal for preventing gun massacres in schools. The plan rejects the gun control measures favored by Democrats and instead proposes posting armed guards in schools.

"The presence of an armed security personnel in a school adds a layer of security and diminishes the response time that is beneficial to the overall security [of that school]," former Rep. Asa Hutchinson (R-Ark.), who directed the NRA task force that crafted its proposal, said Tuesday.