Bloomberg is a self-made billionaire. He is founder and majority owner of Bloomberg News parent, Bloomberg LP. The former Salomon Brothers trader worked his way up to partner there, leading the firm's block trading operations.  In 2001, Bloomberg entered the race for mayor of New York City, creating a controversy when he switched his political allegiance from Democrat to Republican. After successfully campaigning to extend two-term limits, he is currently serving his third consecutive term. He