Alia Beard Rau

The Republic | azcentral.com

If early ballot returns are any indication, Arizona is on track for high voter turnout for Tuesday's presidential primary.

Of the 1.2 million eligible Maricopa County voters, about 894,000 requested early ballots for the presidential preference election, as the primary is officially known. So far, 54 percent or 464,067 have returned their ballots, according to Maricopa County Recorder Helen Purcell.

"That's a pretty good return at this point," she said. "I'm anticipating we will have between a 60 percent and 65 percent turnout. That includes people going to the polls."

Pima County, the state's second-most-populated county, reported it mailed 224,083 ballots to voters and as of Friday, 61 percent, or 136,946, had been returned.

Statewide voter turnout during the past five presidential preference elections has ranged from 30 percent to 51 percent, state election officials said. The high of 51 percent came in 2008, when Arizona primary voters picked Hillary Clinton over Barack Obama and John McCain over Mitt Romney.

Polls are open from 6 a.m. to 7 p.m. Tuesday.

How to vote in Arizona's presidential-preference election

Individuals who have completed but not yet mailed their early ballots should not mail them at this point. Instead, they can drop them off at any polling site on Election Day. Unlike other elections, voters in the presidential preference election can cast their ballots at any polling place in their county. As usual, voters need a photo ID.

Registered independents cannot vote in this election.

"This election is a completely different animal from all the other elections we have in Arizona," Secretary of State Michele Reagan said. "State law requires that voters must be enrolled with a political party to participate. If you are a registered independent, unfortunately you cannot participate."

Azcentral.com will provide results as they start coming in at about 8 p.m. on Tuesday.

Why Arizona's presidential primary matters

Arizona presidential primary turnout

2012: 45 percent

2008: 51 percent

2004: 30 percent

2000: 35 percent