SACRAMENTO — In his campaign for governor, Arnold Schwarzenegger has labeled unions and Indian tribes that operate casinos as "special interests" and rejected their campaign money. But last year, as Schwarzenegger was raising money for a ballot initiative he was promoting, he accepted $530,000 from the California Teachers Assn., one of the most powerful public employees unions in the state. And he hosted a fund-raising brunch for Indian tribes in San Diego, three of which gave a combined $62,000. The donations helped Schwarzenegger's effort to finance the successful campaign for Proposition 49, which aimed to expand before- and after-school programs....