Why do Americans always say they want a politician that 'keeps it real' but dissapprove when one does?

For example, during the elections for the Republicans primaries last year, the candidates were debating in Florida, and every candidate was promising the world. When they got to Ron Paul, he said, I'm not giving you guys the world, instead I plan on reducing the size of government by cutting federal programs even if that means federal jobs in Florida will be lost, and the crowd groaned. Why?