Domingo was active with the Katipunan ng mga Demokratikong Pilinio (Union of Democratic Filipinos, KDP) in the 1970s and 1980s, along with her brother Silme Domingo and other relatives. She lived in communal housing with other KDP members and organized in Seattle and
Oakland. The KDP's work was primarily centered around opposing the
Marcos dictatorship in the Philippines, and Domingo helped lead anti-Marcos demonstrations at the University of Washington. On June 1, 1981, Domingo's brother Silme Domingo was assassinated with his friend and fellow organizer
Gene Viernes in their office at the Local 37 hall. Silme and Gene were both KDP members and reform activists in
ILWU, Local 37 who had worked to challenge racial discrimination in the canneries and corruption in the union. At the time of their assassination, Domingo was living in Oakland and working as a KDP organizer. She moved back to Seattle and for the next ten years chaired the Committee for Justice for Domingo and Viernes. The campaign resulted in the conviction of former Local 37 president Tony Baruso and proved that the assassinations had been organized by the Marcos regime with US government knowledge. == Community organizing ==