| SEIU COPE (SERVICE EMPLOYEES INTERNATIONAL UNION COMMITTEE ON POLITICAL EDUCATION) | $168K | 17 | 2010, 2002, 2006, 2004, 2012, 2008 |
| AFL-CIO | $123K | 27 | 2010, 2002, 2006, 2004, 2012, 2008 |
| AMERICA'S CREDIT UNIONS PAC OF CREDIT UNION NATIONAL ASSOCIATION, INC. | $114K | 31 | 2010, 2002, 2014, 2006, 2004, 2012, 2008 |
| SUPER PAC FOR AMERICA | $87K | 3 | 2010 |
| UNITED FOOD AND COMMERCIAL WORKERS INTERNATIONAL UNION ACTIVE BALLOT CLUB | $73K | 20 | 2010, 2002, 2014, 2006, 2004, 2012, 2008 |
| BLUE DOG POLITICAL ACTION COMMITTEE | $65K | 14 | 2010, 2002, 2014, 2006, 2004, 2012, 2008 |
| UNITED STEELWORKERS POLITICAL ACTION FUND | $63K | 15 | 2010, 2002, 2006, 2004, 2012, 2008 |
| AMERICAN FEDERATION OF STATE COUNTY & MUNICIPAL EMPLOYEES P E O P L E | $63K | 33 | 2010, 2002, 2014, 2006, 2004, 2012, 2008 |
| INTERNATIONAL BROTHERHOOD OF ELECTRICAL WORKERS POLITICAL ACTION COMMITTEE | $60K | 18 | 2010, 2002, 2006, 2004, 2012, 2008 |
| AMERICAN FEDERATION OF TEACHERS, AFL-CIO COMMITTEE ON POLITICAL EDUCATION | $60K | 20 | 2010, 2002, 2006, 2004, 2012, 2008 |