If U.S. Cities and States Can Avoid Default, this Stock Could Double

Sometimes an investment looks like a no-brainer — until you dig a little deeper. On the face of it, Assured Guaranty (NYSE: AGO) looks like one heckuva stock. The company offers insurance policies for bond buyers, focusing on the state and local municipal bond business. It's a good business in normal times and a great business right now, thanks to especially high premiums to insure these increasingly risky bonds. Assured's two main rivals, MBIA (NYSE: MBI) and Ambac Financial (NYSE: ABK) are on the ropes, enabling the company to steal market share . Assured reported second-quarter profits last week of $0.91 a share, roughly +30% ahead of consensus forecasts and a company record since being spun-off from insurance giant ACE (NYSE: ACE) in 2004. And even after a…