High-profile shootings in four southern cities — Chattanooga, Tenn., Charleston, S.C., Chapel Hill, N.C. and Lafayette, La. — in recent months have prompted some lawmakers to call for stricter state and federal firearm controls. But while some states have introduced new requirements for background checks and restrictions on private gun sales, others, such as Kansas and Texas, have expanded access to guns and loosened restrictions for carrying concealed firearms. More than two years after the infamous Sandy Hook Elementary School massacre in Newtown, Conn., that left 20 children and six adults dead, gun-rights advocates have blocked White House plans to introduce new restrictions on automatic rifle ammunition sales. And for the first time in two decades, a majority of the public has indicated support for protecting gun freedoms over restricting guns.