In Chicago, Obama had his biggest impact registering voters on the city's South Side. However, Obama's "Fight the Smears" website disputes this, saying Obama "never organized with ACORN."

After completing his legal education at Harvard in 1991, Obama returned to Chicago to work on the voting project that developed directly out of a radical revolutionary strategy developed by two Columbia University sociologists in the 1960s. In what became known as the Cloward-Piven strategy, the tactic advocated a revolutionary approach to mobilizing the poor in the form of class warfare against capitalist forces viewed as exploiting labor and oppressing the poor. The Cloward-Piven strategy sought to apply the tactics of the revolutionary civil rights movement, including urban riots, to the poor as a whole, transcending interest-group politics defined by race to involve interest-group politics defined by class.