Les Etats-Unis compteraient entre 10 et 20% de libertariens. On lira avec intérêt l'étude du Cato Institute à ce sujet:

Not all Americans can be classified as liberal or conservative. In particular, polls find that some 10 to 20 percent of voting-age Americans are libertarian, tending to agree with conservatives on economic issues and with liberals on personal freedom. The Gallup Governance Survey consistently finds about 20 percent of respondents giving libertarian answers to a two-question screen. Our own data analysis is stricter. We find 9 to 13 percent libertarians in the Gallup surveys, 14 percent in the Pew Research Center Typology Survey, and 13 percent in the American National Election Studies, generally regarded as the best source of public opinion data.