By JERI CLAUSING, ASSOCIATED PRESS

PHOENIX — Arizona voters headed to the polls Tuesday to settle an unexpectedly feisty Republican U.S. Senate primary battle marked by accusations of hypocrisy, broken promises and flip-flopping.

They're picking between the front-runners vying for the GOP nomination to replace retiring Sen. Jon Kyl – six-term U.S. Rep. Jeff Flake and wealthy businessman Wil Cardon.

Tuesday's Arizona elections also will oust of one of two Republican House members, both freshmen pitted against each other by redistricting. Five other House incumbents, including former Democratic U.S. Rep. Gabrielle Giffords' hand-picked successor, face challengers.

Voters in Alaska and Oklahoma also are deciding House races.

In Arizona, Democrats are hoping the surprisingly aggressive – and expensive – challenge from Cardon to Flake, who is widely seen as the favorite in the race, will give them their best shot in years at taking one of the state's two Senate seats.

A push by moderate Democrat Richard Carmona, a former surgeon general under President George W. Bush, comes as the GOP is fighting to pick up four more seats to wrest control of the chamber in advance of votes on key policy issues such as the possible repeal of President Barack Obama's health care law and changes to the tax code.

Arizona hasn't elected a Democrat to the Senate since Dennis DeConcini won his third term in 1988, but Democrats are hoping the primary attacks on Flake have weakened his standing and his bank account.

"Jeff Flake has been a little wounded by the primary," said Jim Pederson, a former Democratic Party chairman who lost an expensive race six years ago to Kyl. "I think a lot of the issues that Wil brought up will kind of resonate with people. I think (the general election) is going to be very close."

Cardon spent $6 million of his own money trying to paint Flake as a Washington insider who reneged on past promises to limit his terms in office. Opponents pointed to Flake's little-known past as a Washington lobbyist for a uranium mine that was minority-owned by Iran. He also criticized Flake, saying he made a dramatic change on immigration, going from a supporter of comprehensive reform to backing policies that would first secure the border.

For his part, Cardon was accused of painting himself as tough on immigration, while a company he partly owned was fined for faulty paperwork in hiring workers with questionable legal status.

Cardon is widely seen as having begun to cede the race in the past month, turning positive in his campaign messages and ending months of expensive television ads.

In Alaska, five Democrats are vying for the chance to challenge Republican U.S. Rep. Don Young, who has held his seat for 40 years. Young has two challengers, but is expected to easily win his primary.

In Oklahoma, two Republicans and two Democrats are vying in runoff elections for their parties' nominations for the seat being vacated by Democratic Rep. Dan Boren.

One or both major parties have primary races in all nine of Arizona's U.S. House districts, including the two-incumbent rivalry between freshman Republican Reps. Ben Quayle and David Schweikert in the 6th Congressional District centered on the Phoenix suburb of Scottsdale. Quayle moved into the district – the bulk of which he previously represented – after redistricting put him in a neighboring district considered more competitive with Democrats.

Barber, a former aide to Giffords, was elected in June to serve out her term after she resigned to concentrate on her recovery from being shot in the head during a January 2011 mass shooting in Tucson.

He faces a challenge from Democrat Matt Heinz, a former Arizona state rep.

___

Associated Press writer Paul Davenport contributed to this report.

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