| DCCC | $188K | 45 | 2006, 2008, 2010, 2012, 2014, 2016, 2018 |
| IOWA DEMOCRATIC PARTY | $81K | 11 | 2010, 2012, 2014 |
| INTERNATIONAL BROTHERHOOD OF ELECTRICAL WORKERS POLITICAL ACTION COMMITTEE | $68K | 28 | 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020 |
| AMERICAN FEDERATION OF STATE COUNTY & MUNICIPAL EMPLOYEES P E O P L E | $66K | 31 | 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020 |
| UAW - V - CAP (UAW VOLUNTARY COMMUNITY ACTION PROGRAM) 'INT'L UNION UNITED AUTOMOBILE AEROSPACE & AGRICULTURAL IMPLEMENT WORKERS OF AMERICA UAW | $66K | 23 | 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020 |
| AMERIPAC: THE FUND FOR A GREATER AMERICA | $65K | 15 | 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020 |
| MACHINISTS NON PARTISAN POLITICAL LEAGUE OF THE INTERNATIONAL ASSOCIATION OF MACHINISTS & AEROSPACE WORKERS | $65K | 13 | 2006, 2008, 2010, 2012, 2014, 2016, 2018 |
| COMMUNICATIONS WORKERS OF AMERICA - COPE POLITICAL CONTRIBUTIONS COMMITTEE | $65K | 23 | 2006, 2008, 2010, 2012, 2014, 2016, 2018 |
| UNITED STEELWORKERS POLITICAL ACTION FUND | $65K | 13 | 2006, 2008, 2010, 2012, 2014, 2016, 2018 |
| CARPENTERS LEGISLATIVE IMPROVEMENT COMMITTEE UNITED BROTHERHOOD OF CARPENTERS AND JOINERS | $65K | 13 | 2006, 2008, 2010, 2012, 2014, 2016, 2018 |