uch publications be marked as such, the Court emphasized that these
provisions were reasonably designed to safeguard the second-class
privilege from exploitation by mere advertising publications. Chief
Justice White warned that the Court by no means intended to imply that
it endorsed the government's "broad contentions concerning the existence
of arbitrary power through the classification of the mails, or by way of
condition * * *"[1144] Again, in Milwaukee Social Democratic Publishing
Co. _v._ Burleson,[1145] where the Court sustained an order of the
Postmaster General excluding from the second-class privilege a newspaper
which he found to have systematically published matter banned by the
Espionage Act of 1917, the claim of absolute power in Congress to
withhold this privilege was sedulously avoided. More recently, when
reversing an order denying the second-class privilege to a mailable
publication because of the poor taste and vulgarity of its contents, on
the ground that the Postmaster General exceeding his statutory
authority, Justice Douglas assumed, in the opinion of the Court, "that
Congress has a broad power of classification and need not open
second-class mail to publications of all types."[1146]

THE EXCLUSION POWER AS AN ADJUNCT TO OTHER POWERS

In the cases just reviewed the mails were closed to particular types of
communication which were deemed to be harmful. A much broader power of
exclusion was asserted in the Public Utility Holding Company Act of
1935.[1147] To induce compliance with the regulatory requirements of
that act, Congress denied the privilege of using the mails for any
purpose to holding companies which failed to obey that law, irrespective
of the character of the material to be carried. Viewing the matter
realistically, the Supreme Court treated this provision as a penalty.
While it held this statute constitutional because the regulations whose
infractions were thus penalized were themselves valid,[1148] it declared
that "Congress may not exercise its control over the mails to enforce a
requirement which lies outside its constitutional province,
* * *."[1149]

STATE REGULATIONS AFFECTING THE MAILS

In determining the extent to which State laws may impinge upon persons
or corporations whose services are utilized by Congress in executing its
postal powers, the task of the Supreme Court has been to determine
whether particular measures are consistent with the general policies
indicated