it's not as though american decline started with donald trump. the seeds of american decline began with eisenhower, were planted with nixon and hit it's peak of backwardsness under reagan. america has been aimlessly drifting like a hopeless opiate addict since the end of the cold war. 

go find literature and popular media from the 1920s. the widespread public rejection of faith in this period in favour of empirical science is really refreshing.

then the depression happened, and world war two allowed for a temporary economic revival, but it's been nothing but a deep embrace of conservatism (including the hippies, who were about as paleo-right as you can get) and widespread social decline for america ever since.