MODESTO -- The sprawling 12th Senate District is known for its pastoral hills that sweep from the Central Valley to the Monterey County coastline -- from Modesto to Salinas -- in a perpetual nod to the state's agricultural heritage.

But here also is the center of raw political maneuvering featuring so much of what defines Sacramento: a legislative leader throwing around his power, gerrymandered lines being used for political advantage, a term-limited legislator seeking his next office, charges of betrayal and intimidation, and the balance of power that even the shift of a single seat could bring.

The political nastiness happening here amid the bucolic peach trees and almond groves is a highly charged recall campaign, led by no less than Senate President Don Perata, D-Oakland, to oust Sen. Jeff Denham, R-Modesto, who stunned legislative Democrats last year when he joined with 13 other Republicans in a bitter 52-day stalemate over the state budget.

Perata accused Denham of betraying the district, where voter registration is 45.7 percent Democratic and 36.3 percent Republican. Immediately after the budget was finally passed, Perata poured $250,000 into the recall campaign to put the issue on the ballot.

Republicans accuse Perata of using bare-knuckles politics to overturn the will of the voters who elected Denham, an almond rancher who owns a business that supplies reusable plastic containers for farmers.

"This is a mean-spirited political trick by Don Perata," said Ron Nehring, chairman of the state Republican Party. "We expect people in the district will stand by him if they know he's being targeted because of his commitment to fiscal responsibility."

Democrats say Denham betrayed his voters by putting schools, health clinics and other services at risk by delaying approval of the budget last year. They also say he has become more conservative as a way to court GOP voters statewide and become a more viable candidate for lieutenant governor in 2010.

"Jeff Denham ran as a moderate but has served as an ultra-conservative," said Gary Robbins, a member of the Stanislaus County Democratic Central Committee and local leader of the recall. "He no longer is a moderate. He no longer pays attention to people here. He's paying attention to the ultra-conservative (people) of Orange County."

He further angered Democrats in January with his key vote that blocked Perata's bill targeting subprime mortgages -- an issue that has plagued Stanislaus County.

Perata stripped Denham of his Agriculture committee chairmanship. It is rare for a member of the minority party to hold a chairmanship, but Perata had granted the perk as a way to entice cooperation from Denham. Perata also took him off the Governmental Organization panel.

But at the heart of the recall -- more than any one thing Denham did -- is the opportunity the district represents for Democrats. They would love to claim the seat. It would move them within one vote of a two-thirds majority -- enough to pass a budget or taxes without GOP support.

"It's Democratic frustration at not having 27 votes," said Tony Quinn, the co-editor of California Target Book, referring to the number of votes required to reach the two-thirds threshold. "This is all about the fact they were so embarrassed over the budget."

It also matters greatly that the 12th Senate district is a rare species in California politics: It is competitive. In fact, the Democratic registration advantage results from a configuration that Democrats worked out in the 2001 redistricting.

Their plans went awry in 2002, when Assemblyman Dennis Cardoza -- the presumptive shoo-in to win the Senate seat -- instead ran for embattled Congressman Gary Condit's seat. That left Democrats with Rusty Areias, the former Los Banos assemblyman whose personal baggage left him vulnerable. Denham won by 1,825 votes in one of the costliest legislative races in history.

"For us, it's about one district and one senator," said Paul Hefner, spokesman for the recall who works for Perata's political consultant, Sandi Polka. "More Democrats is always better, but this is about one senator and the promises he's broken."

Ironically, the one district that Democrats think they can flip because of its partisan breakdown may also be one that is especially resistant to a recall campaign.

It has to do with the conservative, rural outlook of residents, said Robert Benedetti, a political science professor at the University of the Pacific in Stockton, even for Democrats who live in more urban areas such as Modesto.

"As people from an agricultural background, they deal with unpredictable things like the weather -- they take great risks with nature," Benedetti said, "so if they can keep their social and political life the same, they can deal with the fact they can't predict nature."

Larry Powell, a Modesto Democrat, questioned whether the recall is fair play -- particularly after Denham has been elected twice.

"It comes across like a power struggle," said Powell, the owner of 11th Street Barber in downtown Modesto. "These aren't grass-roots recalls. They're originated up there (in Sacramento). That's one reason I don't like it.

"A guy should be able to vote his own conscience," he said. "I don't know what politics Denham was manipulating, but if he's thinking about what's best for California and our area, I don't have a problem with it."

Republicans say it will be difficult to summon voter outrage absent any egregious conduct -- especially if voters are in line with Denham's fiscal conservatism.

"Denham didn't vote for a badly out-of-balance budget and was proven right with the $14.5 billion deficit," said Tim Clark, spokesman for Denham's campaign against the recall, which has raised more than $600,000. "It's exactly the type of representation they want."

Voters, Clark said, will "be motivated and will respond negatively to outside forces coming in and using outside signature gatherers and outside money to defeat their senator."

If the signatures are verified, Gov. Arnold Schwarzenegger will decide when the recall election should occur. Most expect it to be consolidated with the June 3 statewide primary.

Voters in the 12th District would face two questions on the ballot: Should Denham be recalled?, Who should replace him? So far, one Democrat -- former Monterey County Assemblyman Simon Salinas -- has expressed interest in Denham's seat. No Republican is expected to submit a candidacy. If the recall is successful, the person with the most votes wins and would serve out the remainder of the term through 2010.

And Democrats would be one vote closer to a two-thirds majority.

Reach Steven Harmon at sharmon@bayareanewsgroup.com or 916-441-2101.