PHOENIX — Attorney General Terry Goddard formally became a candidate for governor Friday.

Gubernatorial candidate Terry Goddard

Legal papers filed with the Secretary of State’s Office converted what had been an “exploratory committee’’ to a full-blown campaign. The move allows him to now start gathering the signatures to put his name on the ballot for the Democratic nomination.

But Goddard, who has dodged questions about his policies for weeks by saying he was only exploring getting into the race, refused to make himself available after the filing. Aide Rodd McLeod said the campaign is planning a formal media announcement in the coming weeks.

At this point Goddard is the only high-profile Democrat in the race to oust incumbent Republican Jan Brewer.

But he may not get to run against her. She faces opposition within her own party from state Treasurer Dean Martin, former Board of Regents President John Munger and Paulden business owner Owen Buz Mills.

This will be Goddard’s third attempt to gain the post that his father, Sam, held in the 1960s when governors served two-year terms.

He was the Democratic nominee in the 1990 campaign. That race was forced into a 1991 runoff because an independent candidate resulted in no one getting the required 50 percent plus one for election.

Goddard lost that runoff to Republican Fife Symington.

Four years later he lost the Democratic primary to Chandler supermarket chain owner Eddie Basha who, in turn, lost the general election to Symington.

In November, when he first formed his exploratory committee, Goddard said he could provide better leadership than Brewer in resolving the state’s financial hardship and the current $2 billion deficit. But he repeatedly sidestepped questions seeking details.

“Specific proposals are going to have to wait until I become a candidate, if I make that decision,’’ he said at the time.

And Goddard, who turns 63 next week, would not say if he supports Brewer’s proposal for a temporary one-cent hike in the state’s 5.6 percent sales tax, a move the governor said is necessary to get Arizona through the recession.

That lack of detail has not gone unnoticed by Brewer who, during her State of the State speech, chided her political foes for taking pot-shots but having no realistic alternatives.

Prior to his gubernatorial bids, Goddard had been mayor of Phoenix. He was elected attorney general in 2002 and won reelection four years later.

He is constitutionally prohibited from seeking a third term.