Esther Sullivan: America's most invisible communities -- mobile home parks

Here's a fact: Not a single American working full-time for minimum wage can afford to buy a one-bedroom home. For many, mobile homes offer a way to break into homeownership. But owning a mobile home is risky, because these communities are virtually invisible and have few rights. Sociologist Esther Sullivan lists the reasons why mobile homeownership is so insecure, and discusses ways to preserve one of America's best options for affordable housing.