Leading Union Political Campaign Contributors 1990-2010 Democrats Republicans American Fed. of State, County, & Municipal Employees $40,281,900 $547,700 Intel Brotherhood of Electrical Workers 29,705,600 679,000 National Education Association 27,679,300 2,005,200 Service Employees International Union 26,368,470 98,700 Communication Workers of America 26,305,500 125,300 Service Employees International Union 26,252,000 1,086,200 Laborers Union 25,734,000 2,138,000 American Federation of Teachers 25,682,800 200,000 United Auto Workers 25,082,200 182,700 Teamsters Union 24,926,400 1,822,000 Carpenters and Joiners Union 24,094,100 2,658,000 Machinists & Aerospace Workers Union 23,875,600 226,300 United Food and Commercial Workers Union 23,182,000 334,200 AFL-CIO 17,124,300 713,500 Sheet Metal Workers Union 16,347,200 342,800 Plumbers & Pipefitters Union 14,790,000 818,500 Operating Engineers Union 13,840,000 2,309,500 Airline Pilots Association 12,806,600 2,398,300 International Association of Firefighters 12,421,700 2,685,400 United Transportation Workers 11,807,000 1,459,300 Ironworkers Union 11,638,900 936,000 American Postal Workers Union 11,633,100 544,300 Nat’l Active & Retired Fed. Employees Association 8,135,400 2,294,600 Seafarers International Union 6,726,800 1,281,300 Source: Center for Responsive Politics, Washington , D.C.
