On Morning Joe, the panel spoke with national political reporter Robert Costa of The Washington Post about his experience covering the campaign of Republican presidential candidate Donald Trump. Asks veteran columnist and MSNBC contributor Mike Barnicle: “Does anybody have a stronghold on Donald Trump enough to say ‘you’re wrong,’ ‘don’t say this.’? Does anybody have that kind of influence on him? Hear Costa’s opinion on who — if anyone — has Trump’s ear and can or does influence his decisions. Only on MSNBC.