Gun control advocates scored a victory this week when a Texas House committee advanced a bill that would raise the minimum age requirement to purchase assault-style weapons. The celebration didn’t last long. About two days later, the bill died in the Republican-controlled Legislature that routinely blocks any type of gun control legislation, even though Texas has been the scene of more than a dozen mass murder shootings since Gov. Greg Abbott has been in office. The latest mass murder occurred Saturday at the Allen Premium Outlets , where eight people were killed by a gunman firing an assault-style weapon. Political...