Quote from IShopAtPublix:
Current income tax at the federal level is progressive i.e it increase as a percentage of your income as your income increases (up to the maximum top rate of course)
Any sales tax is inherently regressive, it strikes people who make less the hardest. A rich man does not care about the price of toilet paper or soap (unless he is in the business of hotels or buying/selling those) while a poor man and even middle class person will.
Plus, things like Gas prices and necessities going up in price will hit you harder because there will be a giant sales tax slapped up on it.