Prior to entering federal politics, he served as the Liberal member of the Legislative Assembly of Ontario for the provincial riding of Etobicoke Centre from 2014 to 2018.

These include serving as a board director for Leave out Violence, the Emerging Leaders Network, and Global Grassroots, where he supported emerging female leaders in Rwanda on projects addressing issues such as lack of access to water, domestic violence and health education.

His other legislative roles included parliamentary assistant to the Minister Responsible for Digital Government; commissioner, Board of Internal Economy; and vice-chair, Standing Committee on Finance and Economic Affairs.

[12] In 2017, Baker proposed the Phones Down, Heads Up Act, a bill to fine pedestrians between $50 and $125 for texting while crossing the street.

[16] An annual Government and Community Services Fair was co-hosted every year by Baker and Etobicoke—Lakeshore MPP Peter Milczyn.

[18] On October 30, 2018, Baker announced his intention to seek the Liberal Party of Canada nomination in the federal riding of Etobicoke Centre.