Day to day citizens won’t care and would probably get behind it because its easy to point at bad billionaires who only did bad stuff because they had billions to do those things with. And tax revenue would help their lives so great … tax the rich … easy sell.
The millionaires are basically just upper middle class these days, they might think differently but it’s not hard to construct arguments based on their real life and use things they care about to get them to agree.
The multimillionaires are the toughest sell, but i think it’s probably doable. They aren’t yet detached from reality, they have causes they care about they can’t single handily bankroll. they haven’t gotten rich enough the tenth generation of their families may never need to work, they can be reasoned with.
The hundred million plus will probably on average hate the idea as they are probably in general looking at the continuation of their net worth growth and considering themselves as likely be eventually billionaires themselves… on average. Some will be on board, maybe even a significant percentage but I think the majority wont. The thing is about critical mass. With even a modest percentage of these people and all the rest…
With that aggregate group you can use democracy to make things happen even with the billionaires trying to buy the system. There are rich people on board to pay for counter media propaganda and the voting class do matter to their elected representatives as those people worry about getting votes next time.
A wealth tax at say a hundred million is so much harder to sell than at a billion.
And that’s all before you’d get into how it was structured. It would be almost impossible for the world to stop billionaires hoarding wealth in some foxhole full of gold and diamonds and valuable art and so on… but even just capping personal wealth at a billion and forcing the rest of their wealth into trusts and companies would likely be a net good as the army of money managers and businessmen would spread that money further around the economy than a single billionaire ever could.