Former Rep. J.D. Hayworth’s all-but-official primary challenge to Sen. John McCain (R-Ariz.) has already started to reignite long-simmering tensions within the state’s Republican faithful.

Those divisions — combined with both men’s reputation for bare-knuckle politics, a volatile electorate and a state in financial crisis — equal a recipe for one of the country’s fieriest political contests of 2010.

Most Arizona political observers, however, wager that the primary is going to create more light than heat, predicting that issues such as immigration, national defense and climate change, which have divided the party in the past, will be less salient this cycle given the dire economic straits of the country and the state, which is second only to California in terms of “fiscal peril,— according to a recent Pew study.

They also say McCain is on much surer political footing when it comes to a debate on the economy and spending.

“In this political environment, when spending and fiscal issues are forefront on people’s minds, it will be a challenge for Hayworth to overcome both McCain’s record on being anti-earmarks and his anti-spending positions,— said Sean Noble, a Republican strategist and former chief of staff to Rep. John Shadegg (R-Ariz.).

McCain also has the strong backing of one of Congress’ most outspoken fiscal hawks and a fellow member of the Arizona GOP delegation, Rep. Jeff Flake, who predicted that “fiscal issues will be first and foremost— in the 2010 election.

Asked why he is backing McCain over Hayworth, Flake pointed out a series of votes over the course of the decade — especially those on what he views as pork-filled legislation — that McCain opposed and Hayworth supported.

McCain’s campaign has already signaled that the issue of fiscal conservatism is where it plans to do battle, running radio ads last week in Arizona dubbing Hayworth “one of the biggest spenders in Congress.—

“I viewed it originally as a preemptive strike, as an effort to keep J.D. out of the race,— Noble said of the ads, “but it probably has had the opposite effect.—

Indeed, by week’s end, Hayworth had announced he was canceling his conservative talk-radio show, and Tuesday on MSNBC’s “Hardball— he told host Chris Matthews that “I intend to win the Republican nomination in August of this year.—

Hayworth’s advisers say they are prepared to go head to head with McCain on spending issues.

Hayworth spokesman Jason Rose said there is “hypocrisy— in McCain touting a conservative record on spending when he supported bailing out the banking and mortgage industries in 2008.

However, Rose said the Hayworth campaign expects illegal immigration to continue to be a hot-button issue in the campaign, in addition to the economy and spending.

“In Arizona you can’t ignore the Republican animus against Sen. McCain on immigration, especially when you have someone like Sheriff [Joe] Arpaio supporting J.D. Hayworth,— Rose said, referencing the controversial Maricopa County sheriff whose tactics against illegal immigration have attracted copious media attention as well as a U.S. grand jury investigation.

Hayworth certainly has his supporters, most of whom make up a wing of the state GOP that has long been critical of McCain for taking “maverick— positions and working across the aisle on things like immigration reform, campaign finance reform and climate change legislation.

Rep. Dana Rohrabacher (R-Calif.) cited those differences in endorsing Hayworth on Sunday.

And Rob Haney, Maricopa County Republican Party chairman and a longtime McCain nemesis in Arizona, said conservative activists are rallying around Hayworth.

“We’ve been begging J.D. to get in the race,— he said. “We will campaign to our utmost for J.D.—

Haney said Hayworth easily won a straw poll at the county Republican Party’s most recent meeting; McCain came in fourth, behind Chris Simcox, an activist against illegal immigration, and another little-known GOP candidate.

The Arizona Republican Party is remaining neutral, though McCain has had his share of battles with Chairman Randy Pullen, who has also been active in politics against illegal immigration.

The GOP establishment and its donor base, however, are sticking with McCain, said GOP lobbyist and donor Kevin DeMenna, who was co-chairman of Mitt Romney’s 2008 presidential finance team in the state.

“The donors nationally and certainly in Arizona are not going anywhere,— said DeMenna, who added that Hayworth would likely have to rely on grass roots and “tea party— supporters. His national profile on illegal immigration, however, could help, and Rose said Hayworth expects to have the funds that he needs to run a competitive race.

Flake said he believes “McCain’s support is both broader and deeper than you might believe if you listen to talk radio.—

And recent polling bears out the notion that the anti-McCain segment of the Republican voter base is fairly narrow.

A new poll being released Friday by Arizona-based Behavior Research Center, an independent pollster, found that more than half of registered Republican voters rate McCain’s job approval as “excellent— or “good,— while 31 percent rate it as “fair— and 14 percent as “poor.— The margin of error is a relatively high 5 points.

A Behavior Research Center poll this month also found a softening in Arpaio’s job approval rating, which could indicate less support for strong anti-immigration rhetoric. Arpaio continues to enjoy a positive job rating among registered Republicans, but it has dropped since 2008. And his rating among independents has flipped from positive to negative.

A recent Rasmussen poll also found McCain comfortably ahead of Hayworth, 53 percent to 31 percent, a big shift from November when Rasmussen had McCain leading Hayworth by just 2 points.

Rose chalked the change up to the electorate’s focus on health care, where McCain took a vocal stand against the Obama administration. He said, however, that Hayworth plans to “fault Sen. McCain for not fighting hard enough and for not doing everything procedurally he could on the floor.— And he predicted that “the race will tighten back up and will return to the dog fight it’s going to be.—

Earl de Berge, research director for the Behavior Research Center, agreed that Arizona and its electorate are in “flux— but that while that could create an opening for Hayworth, it could also have the opposite effect.

“If there is a serious horse in the Democratic race, there’s a chance this could work to their benefit,— de Berge said, pointing to that fact that McCain’s job approval among Arizona residents as a whole has sunk to its lowest point since 1994 in the center’s latest poll. The drop can largely be attributed to a drop among Independents and Democrats, perhaps as a result of his more strident conservative rhetoric over the past two years.

The fact that Democrats have yet to field an official challenger indicates they are still counting on a McCain win. But Arizona Democratic Party Chairman Don Bivens said the primary gives his party hope even if McCain succeeds in dispatching of Hayworth.

“I think that anything that drives the Republican candidate — whether it be McCain or Mr. Hayworth — to the right will help the Democrats generally,— he said. “We will be looking to occupy the moderate center.—