It's clear that politicians don't get this from the way they talk about a "mere 1%" wealth tax. None of them would speak of adding a "mere 20%" to the income tax rate, even though that's mathematically the same thing. [2]
But it's not "mathematically the same thing". Taking the 100 dollars allegory Paul raises, for that allegory to be based in reality, someone would need to have 20x their annual salary in wealth. The median salary in the US is 59K per annum. For the 100 dollars allegory to work out to a 20% income tax equivalence, people would need to have just over a million dollars sitting in their bank account. The average American net worth is more like 48K (being generous), which is under a year's salary, with a tonne of people also just living permanently in debt (negative wealth). Interestingly, would a wealth tax mean negative tax (free money) for those many in America living in debt?