The following is a direct quote from the ACLU page at http://www.aclu.com/immigrants/gen/11663res20040806.html
The Immigrants' Rights Project (IRP) of the American Civil Liberties Union works to defend the civil and constitutional rights of immigrants through a comprehensive program of impact litigation and public education. The IRP files constitutional and class action lawsuits protecting the historic guarantee to judicial review, enforcing fair employment practices and maintaining constitutional safeguards against detention practices and biased asylum adjudication. For ten years, the IRP has been at the forefront of every major legal struggle securing immigrants' rights; this role has become particularly crucial since the passage of two 1996 congressional acts implementing the most radical and draconian cutbacks to immigrants' rights ever.
Excuse me, but what the h*ll are “immigrant rights”? The Constitution is for American Citizens! Check the preamble:
We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.