In American constitutional law, a fundamental right is a right that enjoys special protection from interference by the government. Fundamental rights can be enumerated—listed in the Bill of Rights—or unenumerated.
Unenumerated fundamental rights are protected by the due process clauses of the 5th and 14th Amendments to the Constitution. Examples include the right to marry, to procreate, and to live together with family members.
If the government wants to take away or interfere with the exercise of a fundamental right, it must satisfy a demanding test called "strict scrutiny." To meet this test, the government must prove two things.