From what I see of the political circus in the USA, it's all down to money.
So they get the president that has the best financial backing, rather then the president who has the best policies.
There doesn't appear to be much swing voting, with people apparently voting according to party affiliations, rather than a preferred candidate.
Still I'm happy to be set right on these views if I'm wrong.
Just find it all very puzzling and complicated, what with primaries, and electoral colleges, and the campaign apparently going on for about 4 years each time.

JM