Well, if that is what you suspect to have happened and are willing to assign some resources (time, money, etc.), you can always file a complaint and start getting the oversight persons breathing down said power-trip abuser's neck. Voter intimidation and campaign-related intimidation would not find many friends in federal courts or even with the careerists in the DoJ.

One word of warning, law enforcement personnel are not unknown to act out on vendettas for past complaints. Complaint-related insulation is best when you are an absolute law-abider, don't spend too much time in a given jurisdiction, you are not a highly visibile minority and/or your plates cannot be, at first glance, linked to your name (e.g., rental car). The smaller the jurisdiction, the more problems you will have. And local judges have a default disposition to accept law enforcement's word over your word.