The Accidental President by Tom McLaughlin
On a visit to the US things take a strange turn for 12-year-old Ajay when, completely at random and totally by accident, he is sworn in as the new president. Well, I guess he can't be any worse than that guy who had the job before him, right? Wrong. It's quite easy for power to go to your head and Ajay, overwhelmed by it all, goes rogue. Soon he's too busy ordering sparkly capes and enforcing the new national spider plan to spot the dastardly plot unfolding right under his nose.