Everyone is getting too fixated on the individuals in the USA but that allows a classic sleight of hand.
Consider:
1. The Republicans were desperate to get back into power.
2. They were up against the PR dream of the First Female President.
3. To spike her guns they had to put up a cartoon chimpanzee who would be guaranteed to draw all the media attention by saying crazy things.

Consider: Game in play. They (the rank and file Republicans) distance themselves from the Chimp to avoid getting spattered with mud from the pig-wrestling contest thats going down.

Consider: End game. Chimp wins. Republicans now have regained power. Chimp down-tunes claims (although not completely yet).

The Mexico wall is as likely as Obamas promise that Guantanemo Bay would be closed within a year of him taking power. These are just puff-ball claims to win votes.