>(And, also, that if we want to help the poorest off, we need to pull some lever other than tax policy.)

Yes, 100% true. I agree: the resolution obviously lies in pursuing redistribution more aggressively.

I'm just uncomfortable with regressive solutions as a whole. If your answer is "it raises overall revenue which allows more redistribution" I may be persuaded, but again your correlation between Gini coefficients and the regressiveness of a given tax system feels specious at best.

I reserve the right to admit that I am wrong at a later date, however.