AUGUSTA — The Maine Democratic Party has nominated a Portland native who has been working as a party field director to be its new executive director.

Mary Erin Casale replaces Arden Manning, who left the post he held for three years to head up party efforts to win elections in November.

The 28-year-old Casale has served as a field director for the state party since August. She also spent time at a political consulting firm in Washington, D.C., and worked on U.S. Rep. Chellie Pingree’s unsuccessful campaign for the U.S. Senate in 2002.