The principle of natural rights is that governments do not confer rights onto people; rights are derived from nature and are inherent in our being human. We are born with the rights to life, liberty and the pursuit of happiness. They are not grants of governments. A natural right transcends politics, policians and government.
To many, especially on the Left, this is an outdated philosophy that interferes with good-meaning policies passed by well-intentioned politicians. Lawrence Lindsey does an excellent job of rebuffing Treasury Secretary Tim Geithner's view that people earning more are obligated to pay an increasingly greater share of their income in taxes to the government because they have benefitted far more from being an American than those who have not taken advantage of this basic political philosophy.
One can always argue that this ratio should be 10-to-1, that the "privilege" of being governed is worth 10 times as much per dollar of income to someone who is rich than to someone who is middle-class. Once we give up our moral compass of government deriving its powers from the people. we must also give up any empirical compass of how much we must surrender to government. When you begin the argument that being a citizen is a "privilege" for which one should pay ever more, you very quickly find yourself on Friedrich Hayek's "Road to Serfdom."