"This provides safety and protection for workers who oftentimes travel 20 to 50 miles to their jobs," said Alabama state Sen. Roger Bedford, D, who has introduced a parking lot gun law in the state's Republican-controlled legislature.
Bedford said he introduced the measure at the request of constituents. He couldn't point to any incident in which a commuter would have benefited from having a gun in the car.
"The problem we have is that businesses are being allowed to erode and take away our Second Amendment right to bear arms," he said. "The guns would only be allowed for legally licensed people, and they'd have to be locked up and out of sight."
NRA spokesman Andrew Arulanandam didn't return four calls for comment about workplace gun laws.
Opponents say the laws threaten employers' ability to control workplace safety and violate their property rights in the name of gun rights.
Workplace homicides average about 500 a year in the U.S., according to studies by ASIS International Foundation, an Alexandria, Va.-based security professional association, and by the Justice Department. Shootings accounted for 80 percent of workplace homicides between 2005 and 2009, with most involving robberies and 21 percent stemming from employee disputes, according to the 2011 Justice report.
Guns-to-work legislation has failed in 12 states in the past two years, including Alabama, Tennessee, Pennsylvania and South Carolina, where lawmakers say they'll push the measures as legislatures convene next year.
Darrell Scott, a lobbyist with the South Carolina Chamber of Commerce in Columbia, said the bill is widely opposed by the businesses in his state because it limits their ability to control to set policy on their property.
In Tennessee, FedEx, Volkswagen and the Tennessee Chamber of Commerce & Industry worked to defeat or modify the workplace gun law, opposing the NRA and the Tennessee Firearms Association, a group that promotes the right to bear arms.