We’ve had seven left-handed Presidents so far …

James Garfield, 1881
Herbert Hoover, 1929 – 1933
Harry Truman, 1945 – 1953
Gerald Ford, 1974 – 1977
Ronald Reagan, 1981 – 1989
George Bush, 1989 – 1993
Bill Clinton, 1993 – 2001
Barack Obama, 2009 – 2017?

Link to Wikipedia entry on Left-handedness