I don't believe that would be politically tenable. The state / society wants fathers (or at least someone) to pay child support. This kind of law would have a c

I don't believe that would be politically tenable. The state / society wants fathers (or at least someone) to pay child support. This kind of law would have a chilling effect on mothers who claim or simply allow someone to take the child's role as a father, even if they're not sure.