Among the 15 counties on our list is Maricopa County, in the southwestern swing state of Arizona. Maricopa County, home to Phoenix, is the politically competitive heart of one of the key ...

New population estimates released by the U.S. Census Bureau revealed that Maricopa ... County (5,009,302). The latest findings come months after the Census Bureau released numbers showing that ...

While Maricopa County's heat-related deaths were still brutally high in 2024, they showed their first annual decline in a decade.