Phillips co-founded CLIPI in Los Angeles in the early 1970s, focusing on environmental protection, civil rights, and government accountability. He played the pivotal role in bringing together the once‑in‑a‑lifetime, favorable, environmental‑justice settlement in the massive Century Freeway litigation, including the redesign of parts of the freeway corridor, the construction of at least 4,000 housing units for displaced residents, and the inclusion of a transit line, addressing both environmental and minority concerns. Together with Carlyle Hall, Phillips helped shape the statutory and case law basis underpinning the private attorney‑general doctrine as the basis for court‑awarded attorney’s fees in public interest litigation. This legal doctrine authorized the awarding of hundreds of millions of dollars in fees to further public interest litigation throughout the state.