The Senate sparred Thursday over legislation to shield the firearms industry from some lawsuits, rejecting an argument that gun makers and others are liable if they irresponsibly allowed a criminal to obtain a weapon and use it to kill or wound.

"We should not protect those folks from their own reckless conduct, their own negligence," said Sen. Carl Levin (search), D-Mich.

Levin's amendment to allow some suits by victims of gun crimes failed 62-37. The bill's supporters said the proposal would undermine the purpose of their legislation: keeping the gun industry out of financial peril from damage suits.

"What this is all about is trying to drive gun manufacturers out of business," said Sen. John Cornyn, R-Texas.

Levin's amendment was one of the few that Republican leaders were letting the Senate vote on.

When the Senate considered the same bill a year ago, Democrats succeeded in attaching an amendment that would have extended an expiring assault weapons ban. At the National Rifle Association's request, the bill never had a final vote.

Senate Majority Leader Bill Frist, R-Tenn., revived it this week by delaying until the fall final action on a defense bill the Senate was debating. He then used parliamentary maneuvers to block Democrats from getting votes on amendments objectionable to the NRA.

"We're being blocked by the power interests on the other side," shouted Sen. Edward Kennedy, D-Mass. "That's the lockhold that the NRA has."

Democrats did succeed in adding an amendment to require child safety locks to be purchased with every handgun, except those bought by government officials and police officers.

Any violation could be punished by the suspension of the dealer's license, a $10,000 fine or both.