[Malone LaVeigh]

We already have a national system of background checks called NICS that every single FFL holder must use for every firearms transfer.

The trouble "they" have with that is that if that gun is sold or given away after that initial sale, they lose track of it. That form 4473 you fill out when you buy a gun is only useful a a tool to track that firearm while you own it. Universal background checks would have to require some type of registry in order to work.

[TigersEye]

Apparently the "they" you speak of includes Republican pols too.

"Universal background checks" means that Mexico can start smuggling guns back into the U.S. /s