CBS’ Margaret Brennan tried to turn the White House Correspondents’ Dinner shooting into a gun control debate.Acting Attorney General Todd Blanche saw it coming and immediately shattered her narrative on the spot. BRENNAN: “Here in the District of Columbia open carry is not permitted. You just said he travelled from California across country by train.”“At this point, are you thinkin at the federal level, of changing security protocols in any way to, for example, match on trains what you are expe