" Unfortunately, the trading of political influence for money has come back in a big way in American politics, this time in a form that is perfectly legal and much harder to eradicate. Criminalized bribery is narrowly defined in American law as a transaction in which a politician and a private party explicitly agree upon a specific quid pro quo exchange. What is not covered by the law is what biologists call reciprocal altruism, or what an anthropologist might label a gift exchange. In a relationship of reciprocal altruism, one person confers a benefit on another with no explicit expectation that it will immediately buy a return favor, unlike an impersonal market transaction. "
― Francis Fukuyama , Political Order and Political Decay: From the Industrial Revolution to the Globalization of Democracy