LANSING, Mich. (AP) — Attorney General Mike Cox said Wednesday that Michigan needs to slash its business and income taxes by $2 billion annually to speed its economic recovery, a plan he would implement if elected governor in 2010.

The 47-year-old Cox formally kicked off his campaign Wednesday with a series of media interviews. He planned to head to Mackinac Island to participate in a Thursday evening gubernatorial debate being held at the Detroit Regional Chamber Mackinac Policy Conference.

Cox joins a crowded field of Republicans hoping to replace Democratic Gov. Jennifer Granholm, who can't run for re-election because of term limits. Other Republicans already running are U.S. Rep. Pete Hoekstra of Holland, Secretary of State Terri Lynn Land of Byron Center and state Sen. Tom George of Kalamazoo County's Texas Township.

Ann Arbor venture capitalist Rick Snyder is taking preliminary steps to get into the race. Other GOP possibilities include Oakland County Sheriff Mike Bouchard and businessman David Brandon.

Cox said all the candidates are focused on fixing Michigan's ailing economy, but he's the only one to suggest the state should cut Michigan's main business tax in half, saving businesses $1.3 billion, and repeal the $700 million income tax increase that took effect in 2007.

He has said he'd pay for the tax rollbacks in part by changing pensions for new teachers and health insurance for state employees, saving $187 million. The state is facing a deficit of at least $1.7 billion for the fiscal year that starts Oct. 1.

"There's a direct correlation between what the business tax rate is, the fact that we raised everyone's taxes during a recession" and the difficulty in drawing new businesses, Cox told The Associated Press Wednesday after announcing his candidacy on Facebook and Twitter. "It hurt Michigan's reputation."

Cox, George, Hoekstra and Land will participate Thursday evening in the Mackinac Island debate, which is a fundraiser for the Chamber. The only Democrat participating is state Sen. Alma Wheeler Smith.

Lt. Gov. John Cherry, who also is running for the Democratic nomination, will be on the island for the conference but said he's not taking part because he thinks debates should be public events.

Former state Democratic lawmaker John Freeman also is considering getting into the race.

Cox was a political newcomer when he beat Democrat Gary Peters in 2002, winning the post from which Granholm launched her gubernatorial bid that year. After becoming the first Republican state attorney general in nearly half a century, he won re-election by beating Grosse Pointe lawyer Amos Williams in 2006.

Cox, who has four children and one grandchild, created a child support division when he came to the attorney general's office that has collected tens of millions of dollars for thousands of children.

A cold case unit he formed convicted serial killer Coral Watts of a 1979 murder, keeping him from getting out of prison in Texas.

More recently, he has challenged rate increases proposed by Blue Cross Blue Shield of Michigan for health insurance plans covering about 400,000 people who buy their own policies. The company said it needs the increases because it's losing money on them, but Cox argues the 31 percent and 56 percent rate increases being requested are excessive.

"If I think something's the right thing to do, I'll take a stand and work with people," Cox said. "No matter what people say about me, they know where I stand and that I'm willing to fight."

Cox's emphasis on unsolved homicides stems from his 13 years as an assistant prosecutor and homicide unit director in Wayne County. He worked for the Oakland County prosecutor for a couple of years before switching to Wayne County.

The son of Irish immigrants, Cox grew up in Wayne County's Redford Township and now lives in Livonia. His father joined the military after his arrival in the United States and earned his citizenship by fighting in the Korean War. Cox served in the U.S. Marine Corps from 1980-83.

He voted for Democratic presidential candidate Al Gore in 1988, but became a Republican after disagreeing with Democratic candidate Michael Dukakis' stance on defense and spending.

Cox's record could be a draw for voters in a GOP primary, and he has shown in his two runs for attorney general that he can raise money.

But he got caught up in a political firestorm in 2005 when he announced he'd had an extramarital affair several years before. He said trial lawyer Geoffrey Fieger had threatened him and forced him to make public what should have been a private matter.

Oakland County's prosecutor said he didn't have enough proof to show Fieger blackmailed Cox, allegedly to force Cox to stop investigating Fieger for ads he'd run criticizing Michigan Supreme Court Justice Stephen Markman.

Cox said then that he told his wife, Laura, about the affair shortly after he took office in 2003. He ran a radio ad featuring his wife talking glowingly about his accomplishments during his successful 2006 re-election campaign.