Although American labor unions evolved out of poverty, today's typical union worker is relatively affluent. Current Population Survey data show that average annual household earnings in 2002 for full-time union workers were nearly $79,000, nearly double the median of all households (including ones with non-workers), and more than for nonunion worker households. While relatively few union workers are truly "poor," a larger proportion (over one-third for members of teachers' unions) comes from households with over $100,000 in annual income. A puzzle: why do union members tend to support liberal policies and politicians far more than their relative affluence would predict? Perhaps it partly reflects rent-seeking behavior.