The fight between the national leaders of the Service Employees International Union and two of its locals got awfully public yesterday, as hundreds of local union members picketed the East Oakland SEIU office. For the last several months, members of United Healthcare West, a umbrella group of two merged locals, have claimed that SEIU national president Andy Stern has embarked on a brutal power grab, ousting local leaders and replacing them with his cronies. Yesterday, according to the Trib, a mob of angry union folks arrived near the SEIU office, carrying boxes of petitions protesting Stern's practices. But the office was closed, so the locals rallied outside the complex instead. Although national leaders were unavailable for comment, they have in the past accused UHW officials of misusing union dues.