New Haven is the birthplace of former president George W. Bush, who was born when his father, former president George H. W. Bush, was living in New Haven while a student at Yale. In addition to being the site of the college educations of both Presidents Bush, as Yale students, New Haven was also the temporary home of former presidents William Howard Taft, Gerald Ford, and Bill Clinton, as well as Secretary of State John Kerry. President Clinton met his wife, former U.S. Secretary of State Hillary Rodham Clinton, while the two were students at Yale Law School. Former vice presidents John C. Calhoun and Dick Cheney also studied in New Haven (although the latter did not graduate from Yale). Before the 2008 election, the last time there was not a person with ties to New Haven and Yale on either major party's ticket was 1968. James Hillhouse, a New Haven native, served as President pro tempore of the United States Senate in 1801.

Answer this question, if possible (if impossible, reply "unanswerable"): Which former U.S. president have been born in New Haven?
George W. Bush