I don't think that's true. A simultaneous hit of shootings in malls all across the country would have a huge effect. If they were all (or even some) put down by people with lawful carry weapons, it would change the whole dialog on the subject.
Tom Clancy’s novel “The Teeth of the Tiger” had terrorists sneak into the U.S. over the Mexican border, obtain submachine guns, and shoot up four malls around the U.S. One of the malls was Charlottesville, VA, where the terrorists were stopped by the two main characters who happened to be shopping at the mall. Another mall was in Utah, where the terrorists never made it into the mall due to heightened security after the first mall attack and armed citizens.
Imagine the paradigm shift in the gun control debate if that happened.
We might see concealed or open carry mandated by law.
The libtards would be so wee-weed up.