Kind of is though. There's the "no ex post facto" provision, not that they always worry about that of course. Then there's the tax methodology itself, where pretty much everyone not on a campaign trail at the moment at least realize that the "wealth tax" fantasy is blatantly unconstitutional and would require an amendment, and fat chance of that although you never know. They could always get a few years out of it by "shopping" in the right circuits.

Means testing for SS and whatever mandatory medical abomination we're living under by then will hapen way before that does anyway because its just easier. Then they'll come for more, and it will be a lot more, because there is no way what already exists can ever be paid for and they intend to expand everything and extend it to everyone on earth who wants to come and partake. Fun times.