Airline mega-merger story is all about Trump

United Airlines CEO Scott Kirby floated the idea of a merger with American Airlines while meeting with President Trump last month, according to multiple reports.Why it matters: Corporate America has concluded that federal antitrust approval now comes from the top.The big picture: Airline mergers must be approved by both the Justice Department and Transportation Department.Many of DOJ's top antitrust officials and prosecutors have been forced out and/or resigned this year, after balking at propos...