But she worked as bartender[1] - which is one of those jobs that teaches you how "Fuck Around, Find Out" works in real life, very quickly. Again, it's not matter of social or economic status, but coming to understand extremely diverse social dynamics outside of the academic field.
Both her and the dock workers were pretty effective in their causes because they have experienced first-hand how going for an half-assed or whimsical approach even in everyday politics bites you hard.
[1]Also wikipedia says that her mother was a house cleaner and school bus driver?