If nothing else the absence of a theoretically desirable wealth tax serves as a justification for progressive income taxes and higher capital gains taxes.
A wealth tax isn't unimplementable because of political will but because a lot of assets are illiquid, hard to price, easy to hide, easy to move to another country (hence the call for a global tax, but what if a few countries defect?) or a combination.
As to approaches: "the left" if there is such a thing successfully campaigned for a full confiscation of property, a 100÷ wealth tax if you like, in huge chunks of the world - I don't see a weakness in persuasive ability there. Wasn't a great idea though. A smaller wealth tax is a better idea, but still not great. Baker who one can agree or disagree with has better policy ideas, or at least better thought-out and consistent ones IMO.