Why does the NRA not want registration of 2 or more assault rifles bought near the Mexico border?

Handguns are already under that requirement, and assault rifles are long ranged and just as deadly if not more, so . . . if the handgun law isn't an invasion of privacy for "law abiding citizens" as the NRA put it, then why would law abiding citizens fear an assault rifle registry when these weapons ARE PROVEN to be killing in Mexico, and sometimes our own BPA. Does the NRA care more about profits than life (human life)?