In Ex parte Rapier31 it was again argued that Congress was without the constitutional power to forbid the use of the mails to lottery tickets, circulars, etc., but this time upon the ground that Congress was without the power to declare the lottery itself a criminal enterprise, "Where Congress cannot by direct legislation pronounce a business to be a crime and punish it as such, counsel argued. "it is not competent to Congress to determine it to be a crime, and to deprive it of the benefit of the mails for the sole purpose of endeavoring to suppress it" To this the court replied: "The States before the Union was formed could establish post-offices and post-roads, and in doing so could bring into play the police power in the protection of their citizens from the use of the means so provided for purposes supposed to exert a demoralizing influence upon the people. When the power to establish post-offices and post-roads was surrendered to the Congress it was as a complete power, and the grant carried with it the right to exercise all the powers which made that power effective. It is not necessary that Congress should have the power to deal with crime or immorality within the States in order to maintain that it possesses the power to forbid the use of the mails in aid of the perpetration of crime and immorality. The argument that there is a distinction between mala prohibita and mala in se, and that Congress might forbid the use of the mails in promotion of such acts as are universally regarded as mala in se, including all such crimes as murder, arson, burglary, etc., and the offense of circulating obscene books and papers, but cannot do so in respect of other matters which it might regard as criminal or immoral, but which it has no power itself to prohibit, involves a concession which is fatal to the contention of petitioners, since it would be for Congress to determine what are within and what without the rule; but we think there is no room for such, a distinction here, and that it must be left to Congress in the exercise of a sound discretion to determine in what manner it will exercise the power it undoubtedly possesses. We cannot regard the right to operate a lottery as a fundamental right infringed by the legislation in question; nor are we able to see that Congress can be held, in its enactment, to have abridged the freedom of the press. The circulation of newspapers is not prohibited, but the government declines itself to become an agent in the circulation of printed matter which it regards as injurious to the people. The freedom of communication is not abridged within the intent and meaning of the constitutional provision unless Congress is absolutely destitute of any discretion as to what shall or shall not be carried in the mails, and compelled arbitrarily to assist in the dissemination of matters condemned by its judgment, through the governmental agencies which it controls. That power may be abused furnishes no ground for a denial of its existence, if government is to be maintained at all."

31 143 U. S. 110; 12 Sup. Ct. Rep. 374; 36 L. ed. 93.