Haha, nice debate I stirred here. For the record, if I could afford both the 70-200 II and the 85L I'd definitely shoot this with the 85. Obviously a zoom isn't needed in this situation. And anyone who can't shoot a portrait in focus at 7.1 with the 85L shouldn't be shooting the president.
5D3, 8-15 f/4 L, 24L II, 35 f/2 IS, 24-70 f/2.8 II L, 50 f/1.4, 70-200 f/4 IS L, 85 f/1.8, 90 TS-E, 100 f/2.8 L, 135 f/2 L 600EX-RT x2, CS6, LR5