President Barack Obama is set to speak on Thursday about how he will target job creation, housing, law enforcement and education in the poorest U.S. communities, part of his pledge to narrow the gap between rich and poor in America. Obama signaled last month that he plans a new focus this year on income inequality, which he called "the defining challenge of our time", pushing to raise the minimum wage and find new ways to help poor children break out of the cycle of poverty. As part of this effort, Obama will create "promise zones" in San Antonio, Philadelphia, Los...