Almost 20% of the United States GDP is actually made up of Government Spending.
Contrary to popular belief the United States is NOT an example of a pure capitalist state.
The government intervenes quite often to provide schools, food banks, hospitals, universities, roads and even bails out banks and large corporations. The government even has anti-competition and anti-monopoly laws.
A pure capitalist state would mean even lower intervention by the Government and a free hand of Demand and Supply.