Ralph fails to understand that in the US, children are considered wards of the state complete with their own set of rights and representation. "Parental rights" are simply a stop gap that is supposed to keep malicious actors of the state from just yanking away your kids willy nilly for no reason. These aren't rights in the sense of constitutional rights, which are enshrined in federal law, they're state guidelines for a court to decide if your parentage is adequate enough for the pridvledge of raising your own kids. A judge may very well look at the whole situation and decide that since Ralph not only committed acts of abuse against his child but has failed to provide even a semblance of financial support since the separation, that his "parental rights" are either severely limited or outright terminated. Ralph got off lucky with Xander cause he never had the chance to abuse the boy but this thing with May is a whole different kettle of fish.