While the 1993 Brady Handgun Violence Prevention Act requires federally licensed gun dealers to check a buyer's name against the FBI's National Instant Criminal Background Check System before selling a firearm, private sellers are exempt from this law.

Proponents of the president's plan point to statistics from national surveys that estimate that 40 percent of gun sales in the U.S. are private transactions. They have argued that traveling gun shows offer a loophole for anyone who wants to get a gun without submitting to a background check.

David Keene, president of the National Rifle Association, says there is no such thing as a "gun show loophole."

"The impression is that at gun shows people buy guns and there are no background checks needed. That's not true," Keene said at a press briefing in January.