"Think of what Sandy Hook might have been like if a couple of male teachers who had played high-school football, or even some of the huskier 12-year-old boys, had converged on Lanza."
I imagine it would have gone like "Reports coming in indicate that there were 30 people killed in Connecticut, including a pile of fat twelve year olds."
This is a demonstration of the completely unrealistic doublethink that goes on with conservatives regarding firearms. There's this unspoken belief that they firearm only works in the hands of the just.
Easy gun access would allow an elderly woman to fend off a gang of 200 pound, brown skinned muggers but a cold blooded killer with high capacity Bushmaster firing NATO 7.62 can be handled by a washed up jock.
The truth is that firearms confer the tactical advantage to the person who fires first and has the least concern about about collateral damage. This is why armed teachers are almost inconsequential to any school shooter with two braincells to rub together. If the shooter didn't drop the teacher before they even cleared their holster they could avoid return fire as long as they kept themself between the armed teacher and the students, forcing the teacher to fire at a moving target and risking hitting kids with stray shots or penetrating fire.