Although the urgency of the public interest sought to be secured by Congressional power restricting the individual’s freedom, and the social importance and value of the freedom so restricted, “are to be judged in the concrete, not on the basis of abstractions,” a wide range of factors are necessarily relevant in ascertaining the point or line of equilibrium. Among these are:
(a) the social values and importance of the specific aspect of the particular freedom restricted by the legislation;
(b) the specific thrust of the restriction, i.e., whether the restriction is direct or indirect, whether or not the persons affected are few;
(c) the value and importance of the public interest sought to be secured by the legislation — the reference here is to the nature and gravity of the evil which Congress seeks to prevent;
(d) whether the specific restriction decreed by Congress is reasonably appropriate and necessary for the protection of such public interest; and
(e) whether the necessary safeguarding of the public interest involved may be achieved by some other measure less restrictive of the protected freedom.