Margaret Costanza, raised in Rochester by Sicilian immigrant parents, began her career with various clerical jobs before becoming an administrative assistant for a real estate developer. She later moved to San Diego County, where she coached candidates for public office and was appointed as a liaison for women's groups by Governor Gray Davis. After losing her liaison position in 2003, Costanza became a professor at San Diego State University and co-developed the Midge Costanza Institute, which aimed to inspire young people in political and social causes. Throughout her career, she was deeply involved in community organizations and championed policies supporting small businesses, labor rights, environmental conservation, and women's rights.

Margaret Costanza's political identity is marked by a unique blend of local economic advocacy and progressive environmental policies, suggesting an ideologically agile approach. Her commitment to small businesses and fair wages contrasts with her progressive stance on environmental conservation and climate change. Costanza's rhetorical style likely emphasized community and inclusivity, given her deep roots in community organizations and her efforts to inspire young people in political causes. Her policy stances reveal a calculated approach that balances regional economic interests with broader environmental responsibilities.