With regard to Eisenhower, why he did not have an elected position, he was certainly well schooled in politics at the highest levels as his role of Supreme Commander in WW2 put him in close contact with most of the world leaders of that time.
Trump is definitely in uncharted territory here.
He has done business with government all over the world buying and building properties Have you ever looked at a list of what he owns and where it is located ?
Here are the buildings. It does not include the deposits and hotel properties
http://www.trump.com/real-estate-portfolio/