Governor Jan Brewer is now running almost even with her leading challenger, State Treasurer Dean Martin, in Arizona’s Republican gubernatorial primary race.

A new Rasmussen Reports telephone survey of likely GOP Primary voters in the state finds Martin barely leading Brewer 31% to 29%. But 20% remain undecided.

Former state GOP Chairman John Munger captures seven percent (7%) of the vote, while Paradise Valley Mayor Vernon Parker, who dropped out of the governor’s race last week to run for Congress, earns five percent (5%) support. Eight percent (8%) of primary voters prefer some other candidate.

Martin runs best for now against likely Democratic gubernatorial candidate Terry Goddard, the state’s current attorney general.

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In November, Maricopa County Sheriff Joe Arpaio picked up 47% of the GOP Primary vote for governor, followed by Martin with 22%, Brewer with 10% and Munger and Parker with six percent (6%) each. But Arpaio has not indicated any interest publicly in actually entering the race.

Following news that Sarah Palin will campaign for him in Arizona, longtime incumbent John McCain has opened a significant lead over challenger J.D. Hayworth in the Republican Senate Primary contest.

Thirteen percent (13%) of GOP voters now have a very favorable opinion of Brewer, while 12% view her very unfavorably.

Martin is viewed very favorably by 22% and very unfavorably by just two percent (2%).

For Munger, very favorables total four percent (4%) and very unfavorables are the same (4%). Parker is seen very favorably by two percent (2%) and very unfavorably by five percent (5%).

At this point in a campaign, Rasmussen Reports considers the number of people with strong opinions more significant than the total favorable/unfavorable numbers.

Brewer was Arizona’s secretary of state in 2006 and became governor a year ago when President Obama asked her predecessor, Janet Napolitano, to be secretary of Homeland Security. But Brewer’s popularity has suffered even in her own party because of protracted battles over the state budget and has resulted in the intraparty challenges by Martin and others.

Forty-five percent of GOP voters in Arizona approve of Brewer’s performance as governor, while 51% disapprove. These numbers are little changed from November.

Rasmussen Reports also has released data on the 2010 governor’s races in California, Colorado, Florida, Massachusetts, Michigan, Minnesota, New York, Ohio, Pennsylvania, South Carolina and Texas.

In 2008, Rasmussen Reports projected nationally that Obama would defeat John McCain by a 52% to 46% margin. Obama won 53% to 46%. Four years earlier, Rasmussen Reports projected the national vote totals for both George W. Bush and John Kerry within half-a-percentage-point.

In Arizona during the 2008 campaign, Rasmussen Reports polling showed John McCain winning the state by a 51% to 45% margin. McCain defeated Obama 54% to 45%. In the 2006 Arizona governor’s race, Rasmussen polling showed Janet Napolitano defeating Len Munsil 58% to 37%. Napolitano won 63% to 35%. In the 2006 race for U.S. Senate, Rasmussen polling showed Jon Kyl leading Jim Pederson by nine, 51% to 42%. Kyl won by nine, 53% to 44%.

See all Rasmussen Reports 2008 state results for president, Senate and governor. See 2006 results for Senate and governor. See 2004 state results for president.

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