kidnapping, crimes also against the National
Government whenever the offender extends his activities beyond state
boundary lines. The usually cited constitutional justification for such
legislation is that which was advanced forty years ago in the above
quoted Hoke Case.[20]

It has been argued that the cooperative conception of the federal
relationship, especially as it is realized in the policy of federal
subventions to the States, tends to break down state initiative and to
devitalize state policies. Actually, its effect has often been just the
contrary, and for the reason pointed out by Justice Cardozo in Helvering
_v._ Davis,[21] decided in 1937, namely, that the States, competing as
they do with one another to attract investors, have not been able to
embark separately upon expensive programs of relief and social
insurance. Another great objection to Cooperative Federalism is more
difficult to meet. This is, that Cooperative Federalism invites further
aggrandizement of national power. Unquestionably it does, for when two
cooperate, it is the stronger member of the combination who usually
calls the tunes. Resting as it does primarily on the superior fiscal
resources of the National Government, Cooperative Federalism has been,
at least to date, a short expression for a constantly increasing
concentration of power at Washington in the stimulation and supervision
of local policies.[22]

The last element of the concept of Federalism to demand attention is the
doctrine that the National Government is a government of enumerated
powers only, and consequently under the necessity at all times of
justifying its measures juridically by pointing to some particular
clause or clauses of the Constitution which, when read separately or in
combination, may be thought to grant power adequate to such measures. In
spite of such recent decisions as that in United States _v._ Darby, this
time-honored doctrine still guides the authoritative interpreters of the
Constitution in determining the validity of acts which are passed by
Congress in presumed exercise of its powers of domestic legislation--the
course of reasoning pursued by the Chief Justice in the Darby Case
itself is proof that such is the fact. In the field of foreign
relations, on the contrary, the doctrine of enumerated powers has always
had a difficult row to hoe, and today may be unqualifiedly asserted to
be defunct.

As early as the old case of Penhallow _v._ Doane, whic