Here is an interactive map showing the distribution of voters by political party in each of the 58 voting precincts that make up Pima County’s Supervisor District One, currently held by Supervisor Ally Miller. According to the Pima County Recorder’s website, 143,593 voters are presently registered in the district. According to Pima County’s official election results, about 74 percent of District One voters voted in its last election in 2016, in which Miller, a Republican, defeated Democrat Brian Bickel by a margin of about 8.6 percent.

Republicans hold a voter registration advantage of about five percent in District One. Of its 143,593 voters, 53,975 are Republicans, or about 37.6 percent. 46,808 are Democrats, or about 32.6 percent. The remaining 41,590 voters, the vast majority of which do not state a party affiliation, make up about 29 percent.