OTHERS voiced interest in trying for governor or mayor , including : Andres Manuel Lopez Obrador , the popular mayor of Mexico City , whose government is thwarting his effort to run for president ; Kofi Annan of Ghana , the secretary general of the United Nations , who liked living in New York and needed a new beginning ; and John R. Bolton , an undersecretary of state -LRB- originally from Baltimore -RRB- who had said that if the U.N. 's 38-story Secretariat building lost 10 stories , '' it would n't make a bit of difference . ''