No, it's not.  The income tax is a tax on wages.  It's not a tax on people.  Taxes on people are direct taxes.  Taxes on goods- including money- aren't direct taxes.

When Congress first introduced an income tax during the War Between the States, the Lincoln Administration argued it was an excise tax.  The Supreme Court later rejected that with respect to certain kinds of income, prompting the 16th Amendment.  From wikipedia:

The Pollock case

In 1894, an amendment was attached to the Wilson–Gorman Tariff Act that attempted to impose a federal tax of two percent on incomes over $4,000 (equal to $109,000 in 2013).[6] The federal income tax was strongly favored in the South, and it was moderately supported in the eastern North Central states, but it was strongly opposed in the Far West and the Northeastern States (with the exception of New Jersey).[14] The tax was derided as "un-Democratic, inquisitorial, and wrong in principle."[15]

In Pollock v. Farmers' Loan & Trust Co., the U.S. Supreme Court declared certain taxes on incomes — such as those on property under the 1894 Act — to be unconstitutionally unapportioned direct taxes. The Court reasoned that a tax on income from property should be treated as a tax on "property by reason of its ownership" and so should be required to be apportioned. The reasoning was that taxes on the rents from land, the dividends from stocks, and so forth, burdened the property generating the income in the same way that a tax on "property by reason of its ownership" burdened that property.

After Pollock, while income taxes on wages (as indirect taxes) were still not required to be apportioned by population, taxes on interest, dividends, and rental income were required to be apportioned by population. The Pollock ruling made the source of the income (e.g., property versus labor, etc.) relevant in determining whether the tax imposed on that income was deemed to be "direct" (and thus required to be apportioned among the states according to population) or, alternatively, "indirect" (and thus required only to be imposed with geographical uniformity).[16]

Dissenting in Pollock, Justice John Marshall Harlan stated:

When, therefore, this court adjudges, as it does now adjudge, that Congress cannot impose a duty or tax upon personal property, or upon income arising either from rents of real estate or from personal property, including invested personal property, bonds, stocks, and investments of all kinds, except by apportioning the sum to be so raised among the States according to population, it practically decides that, without an amendment of the Constitution — two-thirds of both Houses of Congress and three-fourths of the States concurring — such property and incomes can never be made to contribute to the support of the national government.[17]

Members of Congress responded to Pollock by expressing widespread concern that many of the wealthiest Americans had consolidated too much economic power.[18]




If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and in the next place oblige it to control itself. - Federalist 51