“universal background checks for all gun sales and transfers”....would have had no effect in Newtown.
“the registration of all firearms”...would have had no affect in Newtown.
“bans on high-capacity magazines and possession or sale of guns capable of firing more than 10 rounds of ammunition without reloading.”....Lanza went to several different rooms and fired 152 rounds, which constitutes at least 5 magazine changes...but probably more because he dropped some magazines half full. No first graders tried to tackle him. The only thing that stopped him were other people with guns. This would have had no effect in Newtown.
Or, anywhere else for that matter.