Below are some useful one-liners from the opinions written by Supreme Court Justice Sandra Day O'Conner [except as noted]

"there is a presumption that fit parents act in the best interests of their children."

"In light of this extensive precedent, it cannot now be doubted that the Due Process Clause of the Fourteenth Amendment protects the fundamental right of parents to make decisions concerning the care, custody, and control of their children." "It is cardinal with us that the custody, care and nurture of the child reside first in the parents, whose primary function and freedom include preparation for obligations the state can neither supply nor hinder."

"Accordingly, so long as a parent adequately cares for his or her children (i.e., is fit), there will normally be no reason for the State to inject itself into the private realm of the family to further question the ability of that parent to make the best decisions concerning the rearing of that parent's children."

"The decisional framework employed by the Superior Court directly contravened the traditional presumption that a fit parent will act in the best interest of his or her child."

"In an ideal world, parents might always seek to cultivate the bonds between grandparents and their grandchildren. Needless to say, however, our world is far from perfect, and in it the decision whether such an intergenerational relationship would be beneficial in any specific case is for the parent to make in the first instance."

"As we have explained, the Due Process Clause does not permit a State to infringe on the fundamental right of parents to make childrearing decisions simply because a state judge believes a "better" decision could be made..Accordingly, we hold that §26.10.160(3), as applied in this case, is unconstitutional.." (emphasis added)

"The strength of a parent's interest in controlling a child's associates is as obvious as the influence of personal associations on the development of the child's social and moral character. Whether for good or for ill, adults not only influence but may indoctrinate children, and a choice about a child's social companions is not essentially different from the designation of the adults who will influence the child in school. Even a State's considered judgment about the preferable political and religious character of schoolteachers is not entitled to prevail over a parent's choice of private school." [Justice Souter in his concurring opinion.]

"It would be anomalous, then, to subject a parent to any individual judge's choice of a child's associates from out of the general population merely because the judge might think himself more enlightened than the child's parent." [Justice Souter in his concurring opinion.]

"parents have a fundamental constitutional right to rear their children, including the right to determine who shall educate and socialize them." [Justice Thomas in his concurring opinion.]

"Here, the State of Washington lacks even a legitimate governmental interest--to say nothing of a compelling one--in second-guessing a fit parent's decision regarding visitation with third parties." [Justice Thomas in his concurring opinion.]

Justice Kennedy in his dissenting opinion said, "It must be recognized, of course, that a domestic relations proceeding in and of itself can constitute state intervention that is so disruptive of the parent-child relationship that the constitutional right of a custodial parent to make certain basic determinations for the child's welfare becomes implicated....If a single parent who is struggling to raise a child is faced with visitation demands from a third party, the attorney's fees alone might destroy her hopes and plans for the child's future."