Senator Rubio was first elected as City Clerk in Baldwin Park in 2005, where she focused on providing equal service, transparency, best practices, and protecting democracy for city residents. In 2009, she was elected to the Baldwin Park City Council, where she helped balance the city budget during the recession while protecting vital services like public safety. She also worked on policies that gave women equal representation on city commissions, creating domestic violence programs and implementing tougher environmental rules. Senator Rubio represents District 22 in the San Gabriel Valley, which is in the eastern portion of Los Angeles County. Her district is comprised of the cities of Alhambra, Arcadia, Azusa, Baldwin Park, Covina, El Monte, Industry, Irwindale, La Puente, Monterey Park, San Gabriel, Rosemead, South El Monte, Temple City and West Covina as well as the unincorporated communities of Avocado Heights, Charter Oak, Citrus, East Pasadena, East San Gabriel, Mayflower Village, North El Monte, South Monrovia Island, South San Gabriel, South San Jose Hills, Valinda, Vincent and West Puente Valley.

She is Chair of the Senate Insurance Committee and Committee Member of Energy, Utilities, Communications; Health; Transportation; and Governmental Organization. She is also a Senate Select Committee Member of the Governor's 2019 Report- Wildfires and Climate Change - California's Energy Future; The Social Determinants of Children's Well-Being; Asian Pacific Islander Affairs; Mental Health; California-Mexico Cooperation; and California, Armenia and Artsakh Mutual Trade, Art and Cultural Exchange.

Senator Rubio is a Member of the Latino Legislative Caucus, Legislative Jewish Caucus, Los Angeles Caucus, San Gabriel Valley Caucus and Legislative Women's Caucus.