After 50 years of losing population, Philadelphia's has finally stabilized. It will be several years before there is enough data available to understand why (or if that city will now begin to grow), but ' as the Post-Dispatch's Tim Logan (@tlwriter) points out on Twitter ' some analysts believe that the historic losses of white and black residents in Philadelphia is being offset by waves of new immigrants from Mexico and other Spanish-speaking countries and from Cambodia and Vietnam.
Officials in Philadelphia note that the new residents fill up housing stock, open new businesses in vacant buildings, and lend the vibrancy of their cultures to their new city. They bring their ambitions ' from mom-and-pop storefronts to bio-tech startups.
Immigration has long been the life-force of America's cities, just as cities have been the economic engines of their regions and states. Smart states encourage it.