In case it wasn’t already blatantly obvious, my point is that terrorism in the US is fundamentally associated with “brown” people, and elicits the most immediate and direct attention from governments, whereas mass shootings are almost always committed by white men, and even the worst mass shootings against children elicit no real action.
But yes, guns have been regulated in the past — when? After the Black Panther party brought open carry weapons to the state capitol during a protest.