| Organization (Open Secrets rank) | Total To Dem | Total to Rep | |
| 3 American Fedn of State, County & Municipal Employees | 44,369,104.96 | 482,272.88 | |
| 5 National Education Assn | 30,682,853.84 | 2,073,165.80 | |
| 7 Service Employees International Union | 29,139,860.25 | 777,062.94 | |
| 9 Intl Brotherhood of Electrical Workers | 34,094,136.00 | 710,294.50 | |
| 10 American Federation of Teachers | 29,629,429.92 | 0.00 | |
| 11 Laborers Union | 28,693,591.80 | 2,308,679.80 | |
| 12 Teamsters Union | 28,470,121.86 | 1,636,213.90 | |
| 13 Carpenters & Joiners Union | 27,214,622.60 | 3,164,491.00 | |
| 14 Communications Workers of America | 29,007,394.84 | 0.00 | |
| 16 United Food & Commercial Workers Union | 26,255,811.15 | 0.00 | |
| 18 United Auto Workers | 27,518,823.36 | 0.00 | |
| 20 Machinists & Aerospace Workers Union | 27,077,622.46 | 276,302.27 | |
| 29 National Assn of Letter Carriers | 19,624,308.88 | 2,153,887.56 | |
| 32 AFL-CIO | 18,520,412.50 | 892,550.00 | |
| 40 Sheet Metal Workers Union | 18,895,994.00 | 397,810.40 | |
| 42 International Assn of Fire Fighters | 15,272,628.54 | 3,328,649.81 | |
| 44 Plumbers & Pipefitters Union | 18,099,154.08 | 778,458.24 | |
| 45 Operating Engineers Union | 15,927,764.16 | 2,654,627.36 | |
| 52 Air Line Pilots Assn | 14,427,597.01 | 2,607,397.05 | |
| 57 United Transportation Union | 13,555,924.80 | 1,694,490.60 | |
| 58 Ironworkers Union | 14,073,676.08 | 917,848.44 | |
| 59 United Steelworkers | 15,128,829.54 | 0.00 | |
| 66 American Postal Workers Union | 13,648,006.85 | 430,989.69 | |
| 69 National Air Traffic Controllers Assn | 9,980,717.76 | 2,633,800.52 | |
| 77 Koch Industries | 1,160,999.91 | 11,609,999.10 | |
| 86 Natl Active & Retired Fed Employees Assn | 8,876,945.00 | 2,536,270.00 | |
| Totals | 559,346,332.15 | 44,065,261.86 |
I did leave out the Club for Growth on the Republican side, but even then, it would only add $13M to the Republican total which would change the ratio of 12:1 spending since 1989 to 10:1. If we were to apply an estimate that 40% of union workers would support Republican candidates (as Mike Cornelison points out), that narrows the margin to $335M towards democrats for all the listed organizations and $267M towards republicans. So, maybe keep these numbers in mind the next time a liberal friend of yours spouts off about spending in elections insinuating that it is the GOP that benefits.