 Who exactly is responsible for the willful decision to leave that roof unsecured? Why did they make that decision? And also, crucially, why haven't they already been publicly fired? Really, there are only two plausible ways to explain how this would-be assassin managed to take a position with a direct sight line to the stage only 150 yards away. It's either the grossest, most extreme kind of incompetence and negligence from the Secret Service that we've ever seen, or they were in on it.