Answer:
Under Franklin Roosevelt, the American Government became more involved in the regulation of the economy, drawing inspiration mainly from the ideas of John Maynard Keynes, which are known as keynesian economics.
This ideas hold that capitalism is the most efficient economic system, and that liberal democracy is the most desirable political system. However, capitalism itself has to be regulated by the state, and the government must intervene to prevent economic crisis, or to aid in the recuperation from one.
Neither Roosevelt nor Keynes were in favor of government control over people's personal lives, which is not a characteristic of democracy, but of authoritarian and/or totalitarian regimes such as Nazi Germany or Stalin's Soviet Union.