SAN FRANCISCO (AP) - Advocates are asking Hispanics throughout the state to flex their economic muscle Friday by refusing to go to work, school or stores. The planned statewide boycott, organized by two Southern California advocacy groups, is a response to last week's repeal of a law that would have allowed undocumented immigrants to get driver's licenses. "Latino and immigrant communities don't have to roll over," said Edward Headington, a spokesman for the Mexican American Political Association, one of the organizers of the boycott. "It's saying that there is strength in numbers." At 11.9 million, Hispanics make up about a...