One by one, they took the stage at the National Rifle Association's annual convention and denounced the massacre of 19 students and two teachers at an elementary school across the state. And one by one, they insisted that changing U.S. gun laws or further restricting access to firearms was not the answer."We must not react to evil and tragedy by abandoning the Constitution or infringing on the rights of our law-abiding citizens," said Texas Sen. Ted Cruz, who was among the Republican leaders who lined up to speak before the gun rights lobbying group Friday as hundreds of protesters angry about gun violence demonstrated outside.