The American Civil Liberties Union is composed of two entities: the ACLU Foundation, a non-profit with an emphasis on litigation and communication efforts, and the ACLU itself, which participates in legislative lobbying. The latter is not considered a non-profit organization.

Ideology

The ACLU functions on the principle that the American system of governance is founded on "two counterbalancing principles: that the majority of the people governs, through democratically elected representatives; and that the power even of a democratic majority must be limited, to ensure individual rights." The main sources of preventing this potential tyranny of the majority are the Bill of Rights, the 13th, 14th, 15th and 19th Amendments. The stated mission of the ACLU is to ensure:

• Your First Amendment rights - freedom of speech, association and assembly; freedom of the press, and freedom of religion.
• Your right to equal protection under the law - equal treatment regardless of race, sex, religion or national origin.
• Your right to due process - fair treatment by the government whenever the loss of your liberty or property is at stake.
• Your right to privacy - freedom from unwarranted government intrusion into your personal and private affairs.