Parliamentary USA- Woodrow Wilson's views aren't changed by the McKinley & TR presidencies and gets the US to become a parliamentary system with a figurehead president
Presidents
1912-1916: Thomas Marshall (Democrat)
1916-1920: William J. Bryan (Democrat)
1920-1923: Warren Harding (Republican)- died in office
1923-1927: Leonard Wood (Republican)- died in office
1927-1932: Charles E. Hughes (Republican)
1932-1941: William McAdoo (Democrat)- died in office
1941-1944: John Garner (Democrat)
1944-1952: Henry Morgenthau (Democrat)
1952-1960: Dwight Eisenhower (Republican)
1960-1965: Adlai Stevenson (Democrat)- died in office
1965-1968: Allen Ellender (Democrat)
1968-1976: Harold Stassen (Republican)
1976-1980: Terry Sanford (Democrat)
1980-1988: Ronald Reagan (Republican)
1988-1992: Alexander Haig (Republican)
1992-2000: Douglas Wilder (Democrat)
2000-2008: Colin Powell (Republican)
2008-2009: Edward Kennedy (Democrat)- died in office
2009-: Al Gore (Democrat)
Prime Ministers
1912-1919: Woodrow Wilson (Democrat)- resigned due to health problems
1919-1923: William McAdoo (Democrat)
1923-1925: Frank Lowden (Republican-Farmer-Labor-Prohibition)
1925-1932: William McAdoo (Democrat)
1932-1945: Franklin Roosevelt (Democrat)- died in office
1945-1952: James Byrnes (Democrat)
1952-1960: Harry Truman (Democrat)
1960-1963: John F. Kennedy (Democrat)- assassinated
1963-1968: Lyndon Johnson (Democrat)
1968-1970: Hubert Humphrey (Democrat)
1970-1974: Richard Nixon (Republican)
1974-1980: Henry "Scoop" Jackson (Democrat)
1980-1986: Edward Kennedy (Democrat)
1986-1987: Gary Hart (Democrat)- resigned
1987: Michael Dukakis (Democrat)
1987-1991: George H.W. Bush (Republican)
1991-1994: Bill Clinton (Democrat)
1994-1998: Newt Gingrich (Republican)
1998-2001: George W. Bush (Republican)
2001-2004: George W. Bush (Republican-Libertarian)
2004-2009: John Kerry (Democrat)- resigned
2009-2010: Barack Obama (Democrat)
2010-: Mitt Romney (Republican)
note: The dominance of the Democratic Party from 1912 to around the mid-1980s was due to the Solid South voting overwhelmingly Democrat in every election, thus making it almost impossible for the Republicans to get the necessary amount of seats needed for a majority.