In Tuesday's 'primary', Arizona's independent voters don't get much of a say

In Arizona, the electorate is divided into thirds, split roughly equally among Republicans, Democrats and independent voters. But when Arizonans head to the polls Tuesday to cast their vote for presidential nominees, all those independent voters have to stay home.

That's not the case in most Arizona elections.

For example, in the state's upcoming July 30 primary, registered Republicans can vote for Republicans, and registered Democrats for Democrats.

If you're an independent, you have the option to select a party primary to participate in – either by requesting an early ballot, or picking a Republican or Democratic ballot when you head to the polls.

But this election?

"We call it a preference election as opposed to a primary," said Eric Spencer, who served as the state's elections director under a previous GOP administration.

There's two reasons for that. First, tomorrow's vote isn't binding. The Republican and Democratic parties meet separately to select delegates for this summer's presidential nominating conventions. And state law only requires those delegates to make their best effort to cast votes for the winners of the respective parties' popular vote in Arizona.

But the simpler reason, and one election officials in Arizona go to great lengths to explain to voters every four years, is that unlike other primaries, independents aren't invited.

"For the PPE, or the Presidential Preference Election, only registered party members are allowed to participate," Spencer said.

'As many voters as possible'

It was Arizona voters who decided to let independents play in primaries when they approved a ballot measure in 1998.

"It's a western state. So, there's sort of that independent spirit that's always kind of flowing through