Robert H. Jackson, Public Service Commission of Utah v…
“ Anticipatory judgment by a federal court to frustrate action by a state agency is even less tolerable to our federalism. Is the declaration contemplated here to be res judicata, so that the Commission can not hear evidence and decide any matter for itself? If so, the federal court has virtually lifted the case out of the State Commission before it could be heard. If not, the federal judgment serves no useful purpose as a final determination of rights. ”
