The terms used to designate political families are not immutable. They can vary according to geographical and historical context. This can lead to confusion.

In Europe and the United States, certain words no longer have the same meaning. Such is the case with the word liberalism.

In North America, liberalism is classified on the left and equated with progressivism. Indeed, American liberals have become advocates of state intervention and Big Government. This historical evolution is in stark contrast to the continuing meaning of the terms liberal and conservative in Europe.

Indeed, in many countries, particularly in Europe, the term liberalism is associated with laissez-faire economic policies and reduced state intervention.

This is why the term liberals is misleading for a European. American liberal politics, since the 20th century, can be described as a shift towards a statist, authoritarian paradigm, which has distorted the meaning of the word liberalism.

Historically, American liberalism has supported significant state interventionism (Franklin Delano Roosevelt's New Deal and Lyndon B. Johnson's Great Society), including wealth redistribution and social programs. In the USA, the term liberal is therefore associated with left-wing or social-democratic policies, such as public health insurance and public anti-poverty plans.

From the 1960s onwards, supporters of classical liberalism in the USA began calling themselves libertarians to distinguish themselves from American liberals. They are the heirs of 19th-century European classical liberalism.