"The principles governing decision [in this class of cases] have repeatedly been announced and were not questioned below.[751] In the exercise of its police power the State may provide for the supervision and regulation of public utilities, such as railroads; may delegate the duty to an officer or commission; and may exact the reasonable cost of such supervision and regulation from the utilities concerned and allocate the exaction amongst the members of the affected class without violating the rule of equality imposed by the Fourteenth Amendment.[752] The supervision and regulation of the local structures and activities of a corporation engaged in interstate commerce, and the imposition of the reasonable expense thereof upon such corporation, is not a burden upon, or regulation of, interstate commerce in violation of the commerce clause of the Constitution.[753] A law exhibiting the intent to impose a compensatory fee for such a legitimate purpose is _prima facie_ reasonable.[754] If the exaction be so unreasonable and disproportionate to the service as to impugn the good faith of the law[755] it cannot stand either under the commerce clause or the Fourteenth Amendment.[756] The State is not bound to adjust the charge after the fact, but may, in anticipation, fix what the legislature deems to be a fair fee for the expected service, the presumption being that if, in practice, the sum charged appears inordinate the legislative body will reduce it in the light of experience.[757] Such a statute may, in spite of the presumption of validity, show on its face that some part of the exaction is to be used for a purpose other than the legitimate one of supervision and regulation and may, for that reason, be void.[758] And a statute fair upon its face may be shown to be void and unenforceable on account of its actual operation.[759] If the exaction be clearly excessive it is bad _in toto_ and the State cannot collect any part of it."[760] Dominance of Congress The Supreme Court has never forgotten the lesson which was administered it by the act of Congress of August 31, 1852,[761] which pronounced the Wheeling Bridge "a lawful structure," thereby setting aside the Court's determination to the contrary earlier the same year.[762] This lesson, stated in the Court's own language thirty years later, was, "It is Congress, and not the Judicial Department, to which the Constitution has given the power to regulate commerce * * *."[763] A parallel to the Wheeling Bridge episode occurred in 1945. THE McCARRAN ACT: REGULATION OF INSURANCE