The 4th Congressional District includes portions of Burlington, Mercer, Monmouth, and Ocean counties. Republican Rep. Chris Smith has represented the district since 1981. Smith, of Hamilton, faces a primary challenge from Bruce MacDonald of Yardville. Democrat Lorna Phillipson of Spring Lake Heights is unopposed. This is a staunchly red district, with more registered Republicans than Democrats and unaffiliated voters leaning toward the GOP.