While I agree that one would draw the line somewhere, once we allow Congress to legislate a limit on how much personal wealth is allowable, over time that line would inexorably move down.

For example, the limit on deductibility of home mortgage interest was unlimited. Then when the cost of the deduction became inconvenient to Congress, it was set to no more than the interest on a $1,000,000 balance. Then, when that level proved inconvenient, the limit dropped by another 25% to $750,000. Give it another few decades, and the deduction might go away altogether.

Similarly, federal income tax started out very small, and for a good cause — helping fund military needs during war. Many decades later, tax rates have increased dramatically, and no specific reason is needed to increase or decrease them, other than political expediency.

That’s the slippery slope I’d be much more concerned about, because there’s no way to argue against any particular change, once you’ve agreed in principle that it’s allowable at all.

By the way, lest it sound as if I’m against any and all taxation, that’s not at all the case. I think progressive income tax is an important way to fund those governmental services we need, without further impoverishing the already poor just to allow the wealthy to keep more of their income.

It’s just that once you’ve already taxed people’s income, confiscating wealth they were able to create after tax seems difficult to justify.