After the
Carnation Revolution of 25 April 1974, which overthrew the authoritarian
Estado Novo regime, Santos became part of the first administration of the Setúbal City Council, with responsibility for cultural matters, holding the position until the first municipal elections in 1976. She became a member of the Municipal Assembly of Setúbal in 1979, and was president between 2001 and 2009. Santos joined the
Portuguese Communist Party (PCP) in 1974. In 1980 she was elected to the 2nd Assembly of the Republic, representing the
Setúbal constituency, and continued to be a deputy until 2007, winning nine elections. She was known as a vocal supporter of women's rights and played an important role in drafting relevant legislation, including for the promotion of infertility treatment. Santos was also a member of the PCP's Central Committee from 2000 until 2012. ==Acting==