Using the U.S. Mails as a tool of censorship defied both the letter and the spirit of the Constitution. The U.S. Mail was authorized in that document to exist. However, its monopoly was never intended. Nor was the "interstate commerce" clause in the Constitution intended to be anything other than establishing a free market among the states, eliminating interstate tariffs. However, Federal power has been abused as far back as the Sedition Act of 1798. The U.S. Mail prevented the dissemination of abolitionist literature in the South before the Civil War. Seditious materials were often banned from the mails, particularly during the Civil War and the two World Wars. Today's advocates of "hate crime" laws, who include a majority of the Senate, the RINOs not excluded, would do the same thing to political and religious speech.
Comstock, though not motivated by enforcing morality but in protecting a fellow clergyman, was wrong. Those who would use Federal power to enforce personal morality are also misguided. The fact remains that those who scream the loudest against censorship on sexual matters seem to have no problem in silencing Christians and other moral people, as well as those who advocate what they deem as "hate."
Be that as it may, wheather the calm voice of reason gets filtered out with the screaming is up to you.
...and the unfortunate tailspin continues with the Supremes' ruling that the Texas law against sodomy was un-Constitutional.
Thus, Comstock proves the maxim: bad law makes bad results.