Quote from gwb-trading:
Just about every single politican in the U.S. makes more money when they are in the private sector than when they are in office. You can chose just about any major politican that does not have a large family trust fund and see the same type of result.
When the politican is in office he/she can not be the operating CEO of a company, can not be on a paid speaker circuit, can not be out promoting books/media for sale, and plenty of other limitations on earning income when you are being paid in elected office.
in 1998 George Bush made $250k. When he became president and for his entire 8 years, he made around $800k per year (I think his lowest year as president was $735k) So unlike Obama, he managed to make more money as president.