system
A chat on subreddit /r/PoliticalCompassMemes
human
That would be correct. Since everyone needs to buy certain things (food, clothes, etc.) the tax burden shifts to the poorer people. This would also disincentivize spending and probably tank the economy.   

The better off would benefit since they could afford more durable goods that cost less in the long run. Increased sales tax would encourage them to by better more durable goods and use them for longer.
gpt
The bill included a "pre-bate" for an estimate of living necessities, essentially making the poors tax free at the federal level