Service Employees International Union is a labor union representing about 1.9 million workers in over 100 occupations in the United States , and Canada. SEIU is focused on organizing workers in three sectors: health care , including hospital, home care and nursing home workers; public services ; and property services .SEIU is the fastest growing labor union in the United States and has over 150 local branches. It is affiliated with the Change to Win Federation and the Canadian Labour Congress. SEIU is based in Washington, D.C., and has several internal divisions which include: Communications, Government Affairs, New Media, Organizing, Political, Global Strength, Pension/Benefits, Community Strength, Research, and Legal.The union states that its top priorities are to stand up for working families to help bring economic relief to millions across the country, fix the nation's "broken health care system," and fight to guarantee workers' rights on the job. SEIU is sometimes referred to as the "purple ocean" at political events because of the union's recognizable purple shirts. The union is also known for its Justice for Janitors program and strong support for Democratic candidates. It spent $28 million supporting Barack Obama in the 2008 presidential election, making it the "organization that spent the most to help Barack Obama get elected president."