ed the tax and the question came up before the Supreme Court for
final decision. On behalf of the revenue department it was urged that a
general income tax, operating alike on all classes, did not involve any
violation of the constitutional provision. It was also contended that
such a tax was expressly authorized by the Sixteenth Amendment giving
Congress power to tax incomes "from whatever source derived." The Court
in an exhaustive opinion[4] overruled both these contentions and held
the tax to be a violation of the Constitution.

[Footnote 1: Art. 3, Sec. 1.]

[Footnote 2: Art. 2, Sec. 1, Clause 6.]

[Footnote 3: See 157 U.S., 701.]

[Footnote 4: _Evans v. Gore_, 253 U.S., 245.]

It has often been asserted that a limitation of the federal taxing power
is found in the "due process" clause of the Fifth Amendment of the
Constitution, providing that no person shall "be deprived of life,
liberty, or property without due process of law." This amendment relates
to the powers of the General Government. A similar limitation on the
powers of the states is found in the Fourteenth Amendment. Taxing laws
have frequently been attacked in the courts on the ground that, by
reason of some inequality or injustice in their provisions, the taxpayer
was deprived of his property without due process of law. In cases
involving state laws such objections have sometimes been sustained.[1]
There seems, however, to have been no case in which a federal taxing law
was declared invalid on this ground, and the Supreme Court has recently
remarked that it is "well settled that such clause (viz., the due
process clause of the Fifth Amendment) is not a limitation upon the
taxing power conferred upon Congress by the Constitution."[2]
Nevertheless, it is believed that if a federal tax were clearly imposed
for other than a public use, or were imposed on tangible property lying
outside the national jurisdiction, or were so arbitrary and without
basis for classification as to amount to confiscation, relief might be
obtained under the due process clause of the Fifth Amendment.

[Footnote 1: See, e.g., _Union Tank Line Co. v. Wright_, 249 U.S., 275.]

[Footnote 2: _Brushaber v. Union Pacific R.R._, 240 U.S., 24.]

By far the most important and interesting of the implied limitations of
the federal taxing power remains to be noticed. That is the limitation
which prohibits the National Government from burdening by taxation the
property or revenues or obl