Thomas Campbell, who served a partial term in 1917 and had his election overturned by the Supreme Court of Arizona, returned to contest the Governors office.

Incumbent Governor Hunt declined to run again after the stress of the close elections and the year-long court battle.

[4] Sid Osborne also announced his attention to seek the Democratic nomination in February, as did Fred Colter, the state senator from Apache County.

[6] On July 20, 1918, the last day to do so, Colter officially entered the gubernatorial race when he filed his petition with the Arizona Secretary of State.

[7] On the final day, Lamar Cobb added his name to the list of Democratic primary candidates, bringing the total to five.