judicial hearing on
his claim of citizenship, a person arrested and held for deportation is
entitled to a day in court if he denies that he is an alien.[142] A
closely divided Court has ruled that in time of war the deportation of
an enemy alien may be ordered summarily by executive action; due
process of law does not require the courts to determine the sufficiency
of any hearing which is gratuitously afforded to the alien.[143]

Substantive Due Process

DISCRIMINATION

Almost all legislation involves some degree of classification whereby
its operation is directed to particular categories of persons, things,
or events; and it is partly in recognition of this fact that Amendment
Fourteen forbids the States to deny to persons within their jurisdiction
"equal protection of the laws." But this restriction does not rule out
classifications that are "reasonable"; and the due process of law clause
of Amendment Five is at least as tolerant of legislative
classifications, which would have to be arbitrarily and unreasonably
discriminatory to incur its condemnation.[144] In fact, it does not
appear that the Court has up to this time ever held an act of Congress
unconstitutional on this ground. Thus it has sustained a law imposing
greater punishment for an offense involving rights and property of the
United States than for a like offense involving the rights of property
of a private person.[145] Likewise, a requirement that improved property
in the District of Columbia be connected with the city sewage system,
with different sanctions for residents and nonresidents was upheld over
the argument that the classification was arbitrary.[146] The allowance
to injured seamen of a choice between several measures of redress
without any corresponding right in their employer was held not to deny
due process of law.[147] Differences of treatment accorded marketing
cooperatives in milk marketing orders issued by the Secretary of
Agriculture[148] and the selection of a limited number of tobacco
markets for compulsory grading of tobacco[149] have also been sustained.
The priority of a federal tax lien against property passing at death,
may, without offending the due process clause, be different from that
which attaches to property transferred _inter vivos_ in contemplation of
death.[150]

There are indications, however, that the Court may be prepared to go
further than it has in the past in condemning discrimination as a denial
of due pr