Demographics look OK on Arizona. In 2012 the electorate was 73% white, 19% Hispanic, 8% African-American/other. This poll has it at 74% white, 18% Hispanic, 3% African-American and 5% Asian. Since the Hispanic voter population is growing substantially in Arizona that gives Clinton a lot of room to grow from this poll. I think Trump +2 is right or close to right.
Demographics actually look favorable to Trump compared to the actual Nevada electorate. In 2012 the electorate was 64% white, 19% Hispanic, 9% African-American and 5% Asian. The Nevada poll has 67% white voters when most of the registration increases going on in the state are Democratic and non-white in Clark County (indicating an electorate that will be more diverse than 2012). Jon Ralston has repeatedly said that the voter registration numbers are leading towards a durable Democratic advantage in the state. I think Clinton +2 understates her advantage by 3 or 4 points due to these factors. That would explain why Reid said not to be overconfident (implying that Dems are ahead but not decisively so).
Also of note is that Arizona in 2008 Latinos voted (56-41 Obama) versus 2012 (74-25 Obama). I suspect that not only will the electorate be several points more Latino in 2016 in both percentage of the electorate, as well as the Democratic share of the Latino vote considering Trump's lack of popularity among Latino voters.
