The Supreme Court was wrong. Newdow is the father of the minor -- his actions in court is his right by that simple enternal law, even though he argues for his non-custodial daughter.
And even though Newdow is some nutty atheist, imo, G-d agrees with his Natural Rights to speak for his daughter. After all, G-d assigned him the duty of being the girl's father. It's no light thing to challenge one of G-d's own assignments.
"Non-custodial" is light. More a mockery of "Under God" than anything Newdow has tossed out. A bad ruling.