Former Arizona Democratic Chairman Jim Pederson (search) announced Wednesday his candidacy for a U.S. Senate seat held by Republican incumbent Jon Kyl.

Pederson said he would fight for middle-class families' interests, and contended Kyl has put the interests of oil, insurance, drug and tobacco companies ahead of those of most Arizonans.

"Today, Arizona has one senator who's fighting the broken politics of Washington," Pederson said, referring to Republican John McCain (search). "And then we have Senator Kyl, who's Exhibit A of the problem."

Pederson, a commercial real estate developer, earlier this year stepped down as party chairman after a four-year stint that saw Democrats reclaim the governor's office in 2002.

While Pederson characterized Kyl as beholden to special interests, Republicans immediately branded Pederson as aligned with East Coast liberals in the Democratic Party.

"I am confidant that the voters of Arizona will confirm that Jim Pederson is completely out of touch with their values," said state Republican Party Chairman Matt Salmon (search). "Senator Jon Kyl is an experienced and effective national leader who works tirelessly for the people of Arizona."