Yeah, republicans are going to save the day

[Stoic]

As for the actual law, increased background checks on 18-20 year olds seems like a proposal that would actually target mass shootings as a sizable percentage of them have been within that age range. (It wasn't a mass shooting, but the example that comes to mind is the mentally ill young man who shot Gabrielle Giffords was going from Wal-Mart to Wal-Mart the morning of the shooting, being turned away from the first one.)

Nitpick: the Gabby Giffords shooting was absolutely a mass shooting, with 6 killed and 13 injured by gunfire.