State Attorney General Jerry Brown can begin raising big bucks now that he has launched an exploratory run for governor. According to the Contra Costa Times, the former Oakland mayor can now accept contributions of up to $25,900 as a candidate for governor — a huge increase over the $6,500 maximum he faced as attorney general. Some political observers think Brown may have made the move because former President Bill Clinton endorsed San Francisco Mayor Gavin Newsom recently, thereby possibly providing a boost to Newsom’s fund-raising abilities. But a Brown aide said he also needed to combat the deep-pocketed Republican hopefuls in the race. Both Meg Whitman and Steve Poizner are expected to have huge war chests for next year’s election.