Smokescreen of convenience and lies.
The same senators have been calling for many types of harsher gun laws, and greater restrictions on what the American public could have for decades.
Strong forces behind the original ban.
Back when very few crimes involved rifles let alone the type targeted and most crime and murders involved handguns, you would be bombarded with propaganda about how the weapons they wanted banned were the instrument of street violence. (If they were the instruments of the violence it still wouldn't have justified banning them, as handguns were actually the instrument of the street killings, but the "assault weapons" as defined then were rarely involved. The powers that be simply feared certain weapons more than handguns, it had nothing to do with reducing crime or murders, but making themselves feel more content with having a centralized consolidated monopoly on effective force.)
While the media would show clips of full auto fire, then talk about "assault weapons" which were all semi-auto.
Long before the current crisis in Mexico they were restricting and reducing Americans' firearm rights.
If the problems in Mexico ended tomorrow they would move onto another justification for the banning of increasing types of firearms.
They will try to ban guns from whatever angle they think might work at the moment.
