Members of the Hopi Tribe are voting Thursday on whether to approve proposed changes to their constitution.
The proposal before voters represents a major overhaul of the constitution first adopted in 1936. It hasn’t been amended since 1993.
At least 446 people — or 30 percent of registered voters — must cast ballots for the election to be valid. That means a minimum of 224 votes could determine the election.
If approved, the Hopi government would change from a unicameral system to four branches.
Critics say that making the 12 Hopi villages the fourth branch would undermine the villages’ inherent sovereignty.
Supporters say the changes would help stabilize the government.
Polls are open on the reservation from 7 a.m. to 7 p.m.