Lawmaker Ratings Methodology

Ratings aggregated by The Hill are updated at varying intervals by the organizations that produce them. The Hill has used the most recent numbers, and will update them as new numbers become available. Organizations used are listed below with an indication of when they were updated.
NARAL Pro-Choice America 2009 111th Congress
National Right to Life Center 2009 111th Congress
ACLU 2009 111th Congress
Human Rights Campaign 2008 110th Congress
American Conservative Union 2009 111th Congress
Americans for Democratic Action 2008 111th Congress
Drum Major Institute 2008 110th Congress
Family Research Council 2008 110th Congress
Children's Defense Fund 2007
League of Conservation Voters 2009 111th Congress
Numbers USA 2009-2010
US Border Control 2005-2006
American Public Health Association 2009 111th Congress
Alliance for Retired Americans 2008 111th Congress
AFL-CIO 2008 110th Congress
National Education Association 2009 111th Congress

House: 2008
Senate: 2007

Chamber of Commerce 2008 110th Congress
Club for Growth 2008 110th Congress
NFIB 2008 110th Congress
Americans for Taxpayer Reform 2007
Center Against Government Waste 2008
National Taxpayers Union 2009 111th Congress
CALW 2008 110th Congress
CSP 2008 110th Congress
FCNL 2008 110th Congress
Peace Action 2009 111th Congress
Gunowners of America 2009 111th Congress
Brady Campaign cumulatively rates members of Congress from 1991-present, based on gun legislation each year.