The election was held without a primary, meaning all candidates from all parties ran against one another and the person with the most votes (even if only a plurality) won; there was no runoff.

[3] (list of candidates appearing on the May 22, 2010 State of Hawaii, U.S. Representative District 1 Special Vacancy Election ballot[6]) Democratic leaders conceded that the winner-take-all primary favored the one lone Republican in the race.

The Republican National Committee (RNC) indicated it might directly support Djou with the hope of winning a congressional seat in a historically Democratic state;[7] RNC political director Gentry Collins referred to Scott Brown's victory in a Massachusetts special election for the U.S. Senate in stating: "I think for us to win that seat will send a signal that what happened in Massachusetts is not an isolated event.

Senator Daniel Akaka in 2006 when he was still Representative of the 2nd district,[5] although Case claimed that any bad blood with the Democratic electorate over the primary challenge was gone, according to his internal polling.

Case received support from the Democratic Congressional Campaign Committee while Hanabusa said she hadn't spoken to them since the previous year.

[5] It was unlikely either Democrat would drop out; both represented different views and both already faced off in a 2002 special election for Hawaii's 2nd congressional district, which Case won.