Service Employees International Union
Said to be the fastest-growing trade union in North America, the Service Employees International Union (SEIU) focuses on three sectors of a service economy; it is the largest union in the first two:
- Health care: with more than 1.1 million members in the field, including nurses, LPNs, doctors, lab technicians, nursing home workers, and home care workers
- Property services: with 225,000 members in the building cleaning and security industries
- Public services, with more than 1 million local and state government workers, public school employees, bus drivers, and child care providers
Its president, Andy Stern, announced his retirement in April 2010.
Not surprisingly as the largest union in the sector, SEIU has been active in health care reform. It participated in the March 2009 White House Forum on Health Reform.
Conservative critics have been emphatic that SEIU has great influence on President Obama. On Andrew Breitbart's BigGovernment.com, Mike Flynn claimed, of violence in St. Louis, Missouri, "Evidence is emerging that the events of that day went far beyond St. Louis and may have been part of a nationally orchestrated campaign to intimidate and silence dissent. 
There are relationships between SEIU and ACORN, although ACORN has discontinued national operations.
- SEIU Members Endorse Sen. Barack Obama, Service Employees International Union, 15 February 2008
- Michelle Malkin (21 December 2009), Demcare and the race hustlers: It’s not just about ACORN
- Patrick J. McDonnell (28 January 2010), "Kaiser Permanente workers vote to leave SEIU", Los Angeles Times
- Mike Flynn (9 November 2009), Obama’s Shock Troops: SEIU and Political Intimidation in St. Louis