" `***[T] he Constitution does not require impossible standards'; all that is required is that the language `conveys sufficiently definite warning as to the proscribed conduct when measured by common understanding and practices**'"

That there may be marginal cases in which it is difficult to determine the side of the line on which a particular fact situation falls is no sufficient reason to hold the language too ambiguous to define a criminal offense.

"We think that the language Congress used provides an adequate warning as to what conduct falls under its ban, and marks boundaries sufficiently distinct for judges and juries fairly to administer the law in accordance with the will of Congress."

—statute forbidding coercion of radio stations to employ persons "in excess of the number of employees needed... to perform actual services

—held that a penal statute was not unconstitutionally vague because couched in terms of "the number of employees needed."

We have consistently refrained from passing on the constitutionality of a statute until a case involving it has reached a stage where the decision of a precise constitutional issue is a necessity.'Manifestly, it cannot plausibly be maintained that this is such a case.

While the Constitution requires that criminal statutes define the conduct to be punished, the Constitution does not require impossible standards

That "Congress might, without difficulty, have chosen `[c] learer and more precise language'equally capable of achieving the end which it sought does not mean that the statute which it in fact drafted is unconstitutionally vague. "