Activists Asian Americans United is trying to stop a basketball arena for the Philadelphia 76ers at the edge of Chinatown. Vivian Chang works on a narrow Philadelphia street that would have been consumed by a Phillies stadium had Chinatown activists not rallied to defeat the plan in the early 2000s. Instead of 40,000 cheering fans, the squeals of young children now fill the playground at Folk Arts-Cultural Treasures Charter School, which opened in 2007.“We’re standing right where the baseball stadium would have been,” Chang said in late September.