Arizona first gained a fourth district after the 1970 Census. It covered the entire northeastern portion of the state, from northern Phoenix all the way to the New Mexico border. However, the great majority of its vote was cast in northern Phoenix, which was heavily Republican.
https://en.wikipedia.org/wiki/Arizona%27s_4th_congressional_district#:~:text=Arizona’s%204th%20congressional%20district%20is,located%20entirely%20within%20Maricopa%20County.









