Hawaii has a strong pro-incumbent bias.
This -
1960: Voted for the non-incumbent party by 0.3%
1964: Gave President Johnson 78.8%
1968: Voted for the incumbent party by 21%
1972: Gave President Nixon 62%
1976: Voted for the non-incumbent party by 2.5%
1980: Voted for President Carter by 2.1%
1984: Voted for President Reagan by 12%
1988: Voted for the non-incumbent party by 10%
1992: Voted for the non-incumbent party by 12%
1996: Voted for President Clinton by 25%
2000: Voted for the incumbent party by 18%
2004: Voted for the non-incumbent party by 9%
2008: Gave Obama 72% of the vote
The only exceptions to the "Hawaiian incumbent rule" seem to be 1988, 1992, and 2008 (2004 was an exception because Hawaii was called late, late into the night that year).