Shock and heartbreak engulfed Texas, a day after 19 children and two teachers were gunned down at an elementary school. 

Gun control activists have long demanded action to prevent mass shootings, while Democratic lawmakers have introduced multiple proposals, such as requiring universal background checks. However the filibuster has killed many of those proposals. John Williams, the former Senior News Editor for the U.S. News and World Report, says that gun laws are so difficult to be changed because the Republican Party has always been entrenched in gun rights and it requires 60 senators' vote to change something significant in the U.S.