Democrats
Sen. Hillary Clinton:
American Federation of State, County and Municipal Employees (AFSCME)
International Association of Machinists and Aerospace Workers (IAM)
United Transportation Union
Sen. Chris Dodd:
The International Association of Fire Fighters (IAFF)
Sen. Barack Obama:
United Auto Workers Region 4 (68,000 members)
Sen. John Edwards:
United Brotherhood of Carpenters and Joiners of America (520,000 members)
United Steelworkers (USW) (1.2 million members)
United Mineworkers of America (UMWA) (105,000 members)

Republicans