William Frey of Brookings parses Arizona's demographics:

[T]he state’s swift Hispanic growth has been concentrated in young adults and children, creating a “cultural generation gap” with largely white baby boomers and older populations, the same demographic that predominates in the recent Tea Party protests. A shorthand measure for this cultural generation gap in a state is the disparity between children and seniors in their white population shares. Arizona leads the nation on this gap at 40 (where 43 percent of its child population is white compared with 83 percent for seniors). But the states of Nevada, California, Texas, New Mexico, and Florida are not that far behind.

It's not just a handful of states:

Nationally this gap is 25 percentage points.