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

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

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.