he Court sustained an order of the Secretary of
Agriculture fixing the minimum prices to be paid to producers of milk in
the Chicago "marketing area." The dairy company demurred to the
regulation on the ground of its applying to milk produced and sold
intrastate. Sustaining the order the Court said: "Congress plainly has
power to regulate the price of milk distributed through the medium of
interstate commerce, * * *, and it possesses every power needed to make
that regulation effective. The commerce power is not confined in its
exercise to the regulation of commerce among the States. It extends to
those activities intrastate which so affect interstate commerce, or the
exertion of the power of Congress over it, as to make regulation of them
appropriate means to the attainment of a legitimate end, the effective
execution of the granted power to regulate interstate commerce. _See_
McCulloch _v._ Maryland, 4 Wheat. 316, 421; * * * The power of Congress
over interstate commerce is plenary and complete in itself, may be
exercised to its utmost extent, and acknowledges no limitations other
than are prescribed in the Constitution. Gibbons _v._ Ogden, 9 Wheat. 1,
196. It follows that no form of State activity can constitutionally
thwart the regulatory power granted by the commerce clause to Congress.
Hence the reach of that power extends to those intrastate activities
which in a substantial way interfere with or obstruct the exercise of
the granted power."[468]

In Wickard _v._ Filburn[469] a still deeper penetration by Congress into
the field of production was sustained. As amended by the act of 1941,
the Agricultural Adjustment Act of 1938,[470] regulates production even
when not intended for commerce but wholly for consumption on the
producer's farm. Sustaining this extension of the act, the Court pointed
out that the effect of the statute was to support the market. It said:
"It can hardly be denied that a factor of such volume and variability as
home-consumed wheat would have a substantial influence on price and
market conditions. This may arise because being in marketable condition
such wheat overhangs the market and, if induced by rising prices, tends
to flow into the market and check price increases. But if we assume that
it is never marketed, it supplies a need of the man who grew it which
would otherwise be reflected by purchases in the open market. Home-grown
wheat in this sense competes with wheat in commerce. The stim