> The wealth tax is unconstitutional unless the amount collected is apportioned between states in accordance with their census population.

Or the implementation involves a Constitutional Amendment.

But, sure, just fixing income taxes so that they incorporate the function of payroll taxes within the progressive scheme, and do not favor capital income (but do accommodate irregular income in a manner which is fair by allowing advance and deferred recognition of income to smooth spikes from non-repeated events, which will often involve capital income) is both constitutionally more straightforward and simpler method of shifting the overall tax burden more onto the rich.

Unless... nothing. There is no power to tax wealth in the Constitution.

I’m not American so sorry if I am being naive but can the constitution not be changed?

It can, but takes a great deal of effort. The bar for a constitutional amendment is much higher than, say, winning an election; this is a good thing, as it prevents the constitution from being re-written every four years. A politician may win a presidential or congressional election, but will not likely convince the other half of the nation to support any such policy. Income tax took a constitutional amendment, so yes, directly seizing money from citizens would take one as well.

It can be but it is incredibly difficult to do so if there is not widespread support for the amendment. A partisan issue like this wouldn't have a real hope in the current political climate.

Since there has never been a wealth tax, the matter is up for legal debate.

The NYTimes had an article today about the difference between an income tax and a wealth tax, and how there is a constitutional problem with the wealth tax. https://news.ycombinator.com/item?id=21472442