Muni bonds fund the nation's critical infrastructure, and they are subject to the whims of the market: as demand goes down, interest rates must be raised to attract buyers. State and local governments could find themselves in the position of cash-strapped Eurozone states, subject to crippling interest rates. The starkest example is Greece, where rates went as high as 30% when investors feared the government's insolvency. Sky-high interest rates, in turn, are the fast track to insolvency. Greece wound up st