Just me personally, if a person can take part in society then they are people (and if you treat people as monsters then they'll likely act as monsters, if not for revenge then for survival, and at the same time, incorporating demons/mutants into society can be used against those demons/mutants that refuse to take part, that is they can be allies instead of enemies). This means a certain amount of self-control and general responsibility, of course, but I expect the same of humans that are allowed to direct their own lives (preferably with paying taxes, owning property, having one's own accounts, and things like that, though technically even plenty of humans would fail to be people if they were measured by that standard, and I wouldn't want to hold anyone else to higher standards). Many demons, and even some vampires (who see a point in playing by the rules for the sake of having an easier life, even if they lack a conscience), could do that. That makes them people to me.
Of course if they scorn the opportunity to join with society, seeing humans as just prey and livestock who have no more respect for us than a hunter does for the potentially dangerous animals he hunts, then to hell with them. But ideally I mean by individuals rather than class (unless they have a hive mind or some such). Unfortunately, if demons who refuse to join society are allowed to be hunted down like rabid dogs then plenty of humans (as bad as demons) would target the good (or at least civilized) with the bad, so some sort of protocols would have to be in place to prevent that kind of abuse.
It might be worth noting that I have a pretty cynical view of humanity, btw, and don't think many demons are that much worse than humans...and if humans were not allowed to take part in society then our kind would become demonic itself.