It always worries me when people propose not to tax the poor, because government officials care incredibly much about maximizing tax revenue. It gives them an outright incentive to transfer wealth from the poor to the rich, because then they get a bigger cut of the money.

Wouldn't it be better to tax everybody the same and then help the poor by giving them money directly via a UBI, or direct programs like free mass transit? It would also make taxes a whole lot simpler (you buy a thing, you pay a flat percentage in VAT; no individual tax returns whatsoever) and thereby eliminate a lot of these shell games corporations and billionaires use to avoid paying their share.