PHIL HAMBURGER: When Is a Tax Not a Tax? When it’s a taking, like California’s proposed wealth levy.

California’s proposed billionaire tax is unconstitutional. The ballot initiative calling for one-time retroactive 5% tax on the net worth of the state’s billionaires has prompted much unease, but the legal arguments against it have remained elusive. It’s therefore important to recognize that this tax is an uncompensated taking or at least a deprivation of property without due process, contrary to the Fifth and 14th amendments.

Disgruntled taxpayers often grouse that taxation is state-sanctioned theft, and libertarians frequently complain about regulatory takings. But the billionaire tax is a problem for more basic reasons—reasons that are crucial for all of us, not only the hyperwealthy.

Although taxes are generally lawful, that isn’t true of everything called a tax. Consider a hypothetical Bill Gates Tax (imagined by legal scholars Calvin Massey and Eric Kades) that imposes an income tax of 100% on Mr. Gates and no one else. In form, it’s a tax; in reality, it’s a confiscation.

The example of the Bill Gates Tax is extreme in demanding 100% of income from one person. It’s less extreme, however, than the California tax in taking only income, not wealth, and in being prospective.

Three considerations coincide to make it especially clear that the California proposal is confiscatory.

It’s also an admission that the California machine has stifled growth and now has to confiscate available wealth in order to maintain desired levels of fraud and defalcation.

(Archived version here.)