ATLANTA --- Georgia Attorney General Thurbert Baker on Wednesday joined the crowded field vying to replace Republican Gov. Sonny Perdue in 2010, the most prominent Democrat so far to announce his candidacy.

Mr. Baker, who would be the state's first black governor if elected, was not available for interviews. His spokesman Jeff DiSantis confirmed Mr. Baker's campaign mailed the paperwork Wednesday to enter the race, allowing Mr. Baker to raise money for the election 19 months away.

Mr. Baker, 56, is serving his third four-year term as attorney general after being appointed to the post in 1997 by Gov. Zell Miller. He made history as the first black to hold the state's top law enforcement post.

He's expected to stress his law-and-order credentials and history of cracking down on identity fraud and abolishing parole for violent offenders. His candidacy is just the latest development as the state's political heavyweights eye Mr. Perdue's post.

On the Republican side, Lt. Gov. Casey Cagle, Secretary of State Karen Handel, state Insurance Commissioner John Oxendine and state Rep. Austin Scott, of Tifton, are running. Cobb County Commission Chairman Sam Olens is also considering entering the race.

David Poythress, former commander of the Georgia National Guard, is the only other Democrat in the race. House Minority Leader DuBose Porter and former Gov. Roy Barnes have also said they may jump in.

Mr. Perdue became Georgia's first GOP governor since Reconstruction and the state has become increasingly Republican since he first took office in 2002.

Emory University political science professor Merle Black said Mr. Baker has the kind of moderate, centrist resume a Democrat needs to win a general election in Georgia. But if Mr. Barnes, the former governor, gets into the race he would be the immediate favorite to grab the Democratic nomination, Mr. Black said.

"It's a bold move," Mr. Black said. "By announcing first he really throws down the gauntlet to Barnes."

If Republicans have a bitter primary fight among party titans and Democrats unite behind Mr. Baker he would stand a strong chance, Mr. Black said.

BORN IN ROCKY MOUNT, N.C., in 1952, Mr. Baker graduated from the University of North Carolina at Chapel Hill in 1975. He went on to graduate from Emory University's law school. He managed his own law firm and worked for the U.S. Environmental Protection Agency,

Mr. Baker adopted a tough-on-crime stance at the Capitol, where he served nine years in the state House of Representatives and rose to become Mr. Miller's floor leader. He helped pass Georgia's "two strikes" law, designed to keep violent offenders in jail without possibility of parole. He also succeeded in passing tougher laws to combat financial identity fraud.

He was endorsed by the National Rifle Association in all three of his bids for attorney general.

In 2006, Mr. Baker was selected by his peers as president of the National Association of Attorneys General.

His role as the state's chief law enforcement officer has sometimes put him at odds with the black community and his own party.

Mr. Baker's office has vigorously defended Georgia's voter ID law, which has been criticized as disenfranchising poor and minority voters less likely to have photo identification. And some complain that he has done little to stop Georgia's prisons from filling up with black youths.

He drew protests from black leaders in 1999 when he led the charge to prosecute state Sen. Ralph David Abernathy III, son of the civil rights icon, for misappropriating state funds.

The low-key litigator found himself at the center of a racially charged case again in 2007 when he opposed the release of Genarlow Wilson, who was serving a 10-year mandatory prison sentence for having consensual oral sex with a 15-year-old girl when he was 17.

The Georgia Supreme Court eventually ordered Mr. Wilson released.

Thurbert Baker: Attorney general wants to be the state's first black governor.