In my experience with many conversations with lawyers and fathers facing this sickening problem. Nothing, nothing happens at all. Most are fortunate if their support is not re-evaluated and raised. Many who manage to establish a dismissal, will never see the money already spent.
Why? Because there are no family laws. There are only guidelines. Each judge is compelled to do as he or she wishes. Most do exactly that and 99 out of 100 times, it will not be a favorable outcome for the father or, step-father in these cases. Many, many precedents have been established already… the bench in family court has no compelling reason to set fairness standards.
Thank goodness that the Department of Homeland Security will soon have even more data available to help track down these bastards. Perhaps they’ll be a national “dead-beat-step-dads” database. A 10% fee can be assigned to the monies collected. That could pay for a considerable amount of the cost to run this most important agency.