Marin County Supervisor and chairman of the California Coastal Commission, Steve Kinsey, is poised to recuse himself from an upcoming vote on a contentious project that proposes to erect houses, hotels and retail stores—alongside nature preserves and open space—on 401 acres in Newport Beach, representing Southern California’s largest remaining undeveloped parcel of land. 

Speculation on whether Mr. Kinsey would recuse himself arose following Los Angeles Times reports that revealed he had failed to properly disclose…