During the 1916 election held on November 7, Campbell ran against incumbent George W.P. Hunt who was seeking election to his third term. Initially, Campbell was declared the winner by 30 votes but Hunt refused to vacate the governor's office and both men took the oath of office on December 30, 1916.

Hunt filed suit in the Arizona Superior Court on January 25, 1917, and on January 27, the court declared Campbell de facto governor. Hunt agreed to turn over the office on January 29, but appealed and on December 22, 1917, the Arizona Supreme Court overturned the lower court ruling. Campbell vacated the office on December 25, but also filed an appeal with the Arizona Supreme Court on January 8, 1917, that was denied.