I am surprised by the lack of buzz around Ruben Gallego a Latino Iraq War vet seems like a good fit for rapidly diversifying Arizona.
Gallego will be viable statewide in Arizona once the Latino population becomes a high enough share of the statewide population and are fully mobilized as an electorate (i.e. the perfect storm that re-elected Reid in 2010). Until then he would struggle to hit 40% among this state's predominantly older and whiter electorate, especially the Mormon population.
One thing that makes Arizona difficult for Dems is that Phoenix (while still quite liberal) is one of the less liberal metro areas in the country. A Democrat with a base outside of the Phoenix area would be a stronger statewide candidate.
Phoenix has a slight Democratic lean, but the metropolitan area has a heavy Republican lean. Maricopa County has a heavy Republican lean and hasn't voted Democratic in a presidential election since 1948.