Freakonomics asks:  Why Is Everyone Whining About Taxes?:

We are a low-tax country; our average tax rate, counting all taxes, hovers above 30%. Why do we hear so many more complaints about high taxes than I hear in the European Union, where taxes are a much higher percentage of G.D.P.? …

Joe the plumber pays far lower taxes than Josef or José the European plumber does, so why should Joe’s fellow citizens have any sympathy for him? One economic answer to this question is that we all expect to become rich and don’t want to have very high taxes on our expected large incomes. Yet today, income mobility is no greater in the U.S. than in Europe, so our expectations do not seem rational. What’s the answer? Are we more selfish than Europeans? Are our governments less efficient?