The ACLU advocates freedom of speech, equal protection, fair treatment, and right to privacy. Their site provides comprehensive coverage of a variety of social issues including criminal justice, the death penalty, free speech, HIV/AIDS, immigrants' rights, lesbian & gay rights, racial equality, and much more.
This conservative think tank advocates limited government, individual freedoms, and traditional American values. Their "Research" area covers both foreign and domestic issues, including crime, education, family and marriage, social security, welfare, and much more.
This nonpartisan group focuses on issues that deal with cities and their residents. Topics covered include "Crime / Justice," "Economy / Taxes," "Health / Healthcare," "Housing," and "Welfare." Each issue has numerous full text research reports, which are browsable by author or topic, and keyword searchable; reports are available as a standard webpage or as PDF documents.