This is a nice summary about public sector unions and their positions in a political economy:
Unionized public-sector employment is the distilled essence of the left’s moral ideal. No one has to worry about making a profit. Generous health-care and retirement benefits are provided to everyone by the government. Comfortable pay is mandated by legislative fiat. The work rules are militantly egalitarian: pay, promotion, and job security are almost totally independent of actual job performance. And because everyone works for the government, they never have to worry that their employer will go out of business.