I don't think it was simply a comparison to the present that irked the GP, I think it was the comparison between Trump, who, for all his faults, isn't quite at the level of a guy who had incestuous relations with his sisters, had people killed for amusement, and had a desire to make his horse a consul. It is mostly a harmless admission of the writer's bias - if this was written in the early '70s, there'd be comparisons to Camp David instead of Mar-a-Lago most likely. I don't particularly think it detracts from the piece.