Unger addressed the constitutional issue of whether a parent's right to smoke could be restricted. The court found no constitutional right to smoke thereby making such restrictions permissible. Further, the court found that "upon a showing that the parent's activity may tend to impair the physical health of the child," a parent's constitutional interest could be restricted. Notwithstanding Unger, some have argued for a constitutional challenge on smoking restrictions based on the right of parents to be free from governmental interference in raising their children. See Victoria L. Wendling, Smoking and Parenting: Can They Be Adjudged Mutually Exclusive Activities?, 42 Case W. Res. L. Rev. 1025 (1992). The argument is that in cases where the harm to the child from ETS is slight, or the nexus between the harm and smoking is attenuated, the fundamental right of parents to raise their children may not be superseded. Traditional dominance of parental decision-making and control of their children is axiomatic in American law and culture.

The United States Supreme Court has recognized the fundamental right of parents to raise their children. The courts have also stressed that parents have the right to raise their children according to their own moral choices. In In Re Marriage of Wellman, 164 Cal. Rptr. 148, 152 (Cal. Ct. App. 1980), the California Court of Appeals held that custody decisions should not be based upon disapproval of a parent's morals or other personal characteristics that do not harm or have a significant bearing on the child. Similarly, the Pennsylvania Superior Court found a parent fit despite immoral behavior where the child's development was normal. Michael T.L. v. Marilyn L.J. , 525 A.2d 414, 420 (Pa. Super. Ct. 1987).

When viewed as only a permissible immoral behavior, the issue of cigarette smoking arguably should have no effect on deciding child custody. For instance, in custody disputes involving one parent who drinks or uses illegal drugs, it must be shown both that the parent uses the substances and that this use has a detrimental effect on the child. Similarly, courts have refused to change custody based on extramarital affairs, sexual promiscuity, and exposure of the child to obscene materials. Thus without a showing of clear harm to the child, the constitutional right to raise one's children could overcome any inquiry into the issue of smoking.