powers vested in them, so ordain without infringing any of those fundamental principles of right which make up due process of law, it may, notwithstanding, be true that a system which should give the decision to a body already biased, which in effect should oblige one accused of crime to plead his cause before those who had already prejudged him, would violate those fundamental principles.
It cannot, however, be asserted that on this account every trial in which the jury was not wholly impartial would fail of being due process. Such a provision as the one in question is aimed at the system, and not at the administration of it. It may well be that a State can deprive of life, liberty, and property through its judicial officers as well as through its legislative or executive branches, and if a State court should give a judgment illegal for want of jurisdiction, or kindred cause, it might be a matter cognizable and remediable by the Supreme Court; but if the State creates a system of procedure which offers protection from a partial jury, a system wholly in accord with the Constitution of the United States, and if the State courts administer justice in accordance with that system, select a jury pursuant to the rules there laid down, try the question of partiality by the methods prescribed, surely it can never be said that there has not been due process of law simply because opinions may differ as to the effect that should be given to certain of the evidence introduced to test the incidental question of partiality. Under no other section of the Constitution is provision made for overturning the decisions of the State tribunals for error unless the error is committed in the decision of a question as to the effect of the federal Constitution or the federal laws; in no other class of cases brought before it from a State court for review can the decision of a question of fact or of general law be made the basis for reversing the judgment; a State court may pronounce a contract invalid for any reason except the subsequent enactment of a statute impairing it, and although the decision may be deemed manifestly erroneous it stands as final and subject to no review. Bethell v. Demaret, 10 Wall. 37. The protection of an appeal to the Supreme Court of the United States is elsewhere limited to the correction of erroneous decisions of purely federal questions, and no attempt is made to supply a safeguard against errors, or even against corruption, in the State courts in other matters; yet, under this section