There have long been ideological restrictions on naturalization in United States law. Nativism and anti-anarchism at the turn of the 20th century, the red scare in the 1920s, and further fears against communism in the 1950s each shaped United States nationality law. Though ideological exclusions on entry were largely eliminated in 1990, ideological bars arising from each of these time periods and prior still exist in American naturalization law. This long history has resulted in a naturalization statute that requires naturalization applicants to be "attached to the principles of the Constitution of the United States" (a requirement that has existed since the earliest US immigration laws) and forbids them from adhering to several more specific ideological principles such as totalitarianism,
