The powerful gun lobby is gauging enough support in Congress to block a law that would ban assault weapons, despite promises from the White House and senior lawmakers to make such a measure a reality.

Senators plan to introduce a bill that would ban assault weapons and limit the size of ammunition magazines, like the one used in the December shooting massacre that killed 27 people, most of them children, in Newtown, Conn. Democratic Sen. Dianne Feinstein of California has promised to push for a renewal of expired legislation.

The National Rifle Association has so far prevented passage of another assault weapons ban like the one that expired in 2004. But some lawmakers say the Newtown tragedy has transformed the country, and Americans are ready for stricter gun laws. President Barack Obama has made gun control a top priority. And on Tuesday Vice President Joe Biden is expected to give Obama a comprehensive package of recommendations for curbing gun violence.

Still, the NRA has faith that Congress would prevent a new weapons ban.

“When a president takes all the power of his office, if he’s willing to expend political capital, you don’t want to make predictions. You don’t want to bet your house on the outcome. But I would say that the likelihood is that they are not going to be able to get an assault weapons ban through this Congress,” NRA president David Keene told CNN’s “State of the Union.”

Sen. John McCain, R-Ariz., responded with a flat out “no” when asked on CBS’ “Face the Nation” whether Congress would pass a ban on assault weapons.

Democratic West Virginia Sen. Joe Manchin, a lifelong member of the NRA has said everything should be on the table to prevent another tragedy like Newtown. But he assured gun owners he would fight for gun rights at the same time. “I would tell all of my friends in NRA, I will work extremely hard and I will guarantee you there will not be an encroachment on your Second Amendment rights,” Manchin said on ABC’s “This Week.”

The NRA’s deep pockets help bolster allies and punish lawmakers who buck them. The group spent at least $24 million in the 2012 elections — $16.8 million through its political action committee and nearly $7.5 million through its affiliated Institute for Legislative Action. Separately, the NRA spent some $4.4 million through July 1 to lobby Congress. Keene insists the group represents its members and not just the gun manufacturers, though he said the NRA would like industry to contribute more money to the association.

“We know what works and what doesn’t work. And we’re not willing to compromise on people’s rights when there is no evidence that doing so is going to accomplish the purpose,” Keene said.

The NRA, instead, is pushing for measures that would keep guns out of the hands of the mentally ill, until a person gets better. “If they are cured, there ought to be a way out of it,” Keene said.

Currently, a person is banned from buying a gun from a licensed dealer if the person is a fugitive, a felon, convicted of substance abuse, convicted of domestic violence, living in the U.S. illegally or someone who “has been adjudicated as a mental defective or has been committed to any mental institution.”

States, however, are inconsistent in providing information about mentally ill residents to the federal government for background checks. And, the Brady Campaign to Prevent Gun Violence said some 40 percent of gun sales happen with no background checks, such as at gun shows and by private sellers over the Internet or through classified ads.

(AP)