I ran for president once, but i wasn't noticed enough. So that's why i decided to build up my reputation but i fell in love with being secretary of defense.
Also when people vote for president, they want someone who will make the stream exciting, lots of arguing or change, so that's why they voted for IncognitoGuy. After this term, people will realize they need someone serious so they will vote more logically next term, and during that term they will get bored so they will vote for someone more exciting in the next term. And this pattern will continue to repeat.