Democratic sources say that Lisa Jackson, now the Assistant Commissioner of Compliance and Enforcement, has emerged as a top candidate for Commissioner of Environmental Protection in Jon Corzine’s administration. Jackson worked for the U.S. Environmental Protection Agency from 1987 to 2001, serving as Acting Director of Enforcement in the New York regional office run by state Board of Public Utilities Chairman Jeanne Fox. Jackson has an influential backer: former U.S. Senator Bob Torricelli. This could help Torricelli, who is seeking DEP permits for his client, Matrix Developments. The current Commissioner, Bradley Campbell, may want to stay on — although it won’t necessarily be his choice.