Corruption has never really been an election issue in genteel Somerset County, where Democrats haven’t won a countywide race since Michael Ceponis won a Freeholder race 28 years ago. But now, allegations of mismanagement and wasteful spending by the GOP-controlled Somerset County Park Commission – which led to a subpoena from the state Attorney General’s office – could give Democrat Melanie Marano a great campaign issue in a low turnout year. Marano, a Green Brook Township Committeewoman, faces Green Brook Mayor Patricia Walsh for the Freeholder seat being vacated by Denise Coyle, who is running for the State Assembly.