Arizona's six-way Republican governor's primary is widely seen as a contest between Mesa Mayor Scott Smith and Arizona Treasurer Doug Ducey.
The candidates have spent millions on advertising and crisscrossed the state for months, attending barbecues, chamber of commerce meetings and other events to get their message out.
Early balloting began in July, but the actual election is set for Tuesday. A high turnout of primary day voters -- especially by a large independent bloc -- could give Smith a boost, according to Republican political consultant Bert Coleman.
The other candidates include former Internet company executive and primary dark horse Christine Jones, Secretary of State Ken Bennett, former Maricopa County Attorney Andrew Thomas and former U.S. Rep. Frank Riggs.
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