Presidential contender Rudy Giuliani has edged ahead of John McCain among Republican voters in Arizona, marking a huge change in the GOP hierarchy just three months before Arizona voters cast ballots in the state’s presidential preference elections.

GRAPHIC: Presidential favorites

Read Paul Giblin's blog, Checking In

Most surveys have shown McCain’s support eroding since the beginning of the year, but the independent Rocky Mountain Poll released on Monday was the first major survey that put McCain behind any of his GOP rivals.

The survey pegged Giuliani’s support among Republican voters statewide at 20 percent.

McCain follows two points behind at 18 percent, which is within the survey’s margin of error.

Behind them, Mitt Romney trails at 11 percent support and Fred Thompson registers 10 percent.

On the Democratic side, Hillary Clinton is opening a wide margin among her party’s other presidential contenders. She has 44 percent support, while her nearest rival, Barack Obama, is 30 points behind at 14 percent.

Clearly, though, the major headline from the poll is McCain, said Earl de Berge, research director of the Phoenix-based Behavior Research Center, which conducted the poll.

“He’s a favorite son in Arizona, and for him not to be able to just walk away with the nomination here strikes me as a story in itself,” de Berge said. “He should be head and shoulders above everybody else.”

McCain is running out of time to reverse the downward trend if he hopes to win his own state on Super Duper Tuesday, Feb. 5, when residents in 23 states will vote.

McCain commanded 40 percent support among Arizona Republicans in January, according to the Rocky Mountain Poll. His support slipped to 34 percent in March and crashed this month.

Meanwhile, Giuliani opened at 13 percent in January and has leveled off at 20 percent.

McCain is still feeling a backlash from his high-profile positions in support of the troop surge in Iraq and for the Senate’s attempt at comprehensive border security and immigration reform, de Berge said.

More recently, McCain has adjusted his position on border and immigration issues, saying he supports a border-enforcement-first approach.

Republican political strategist Gordon James, who has been heading up Giuliani’s fundraising efforts in Arizona, said McCain obviously fell out of favor with some Republican voters because of his stance on immigration. But the man who has represented Arizona in the U.S. House and Senate since 1983 still has impressive political clout here, he said.

“I just can’t imagine that he wouldn’t be carrying his own home state. He’s probably still ahead,” said James.

“What we hear is that people are saying, ‘Well, is he really in the race to stay?’ I think he definitely is. And I think if you got to people actually voting, the numbers would be a lot higher,” he said.

McCain’s state campaign co-chairman Matt Salmon could not be reached for comment Monday, though last week he told the Tribune that McCain knows he has to fight for votes in Arizona.

In past presidential campaigns, major candidates usually forfeited a rival’s home state to spend their money and time elsewhere, Salmon said.

This year, though, Romney, Giuliani and Ron Paul have all made barnstorming tours through Arizona to pick up donations and votes.

As a result, McCain has had to spend time here as well, Salmon said. Finishing second to Giuliani or anyone else in Arizona is not an option.

An important factor in McCain’s fall in Arizona is the increase of undecided voters, de Berge said. Uncommitted voters have steadily increased from 12 percent in January to 32 percent this month.

Voters apparently aren’t comfortable with the candidates who have emerged as front-runners and are waiting for another candidate to rise above the pack. Voters may even wait until the first few primaries show some direction, he said.

For now, women voters are tipping the balance in favor of Giuliani, according to the survey.

Approximately 22 percent of women support Giuliani, compared with 14 percent for McCain. In contrast, 25 percent of men favor McCain, while only 16 percent go for Giuliani.

On the Democratic side, Clinton is pulling from a variety of demographics, according to the survey.

She has 70 percent support among Hispanics, 56 percent support among the 35-54 age group, and 36 percent among the 55-and-older segment.

The survey of 800 voters was conducted between Nov. 12 and 15. It has a margin of error of 3.5 percentage points, according to the Behavior Research Center.