@ican711nm,
ican711nm wrote: Absent a better solution, I recommend a "flat" federal sales tax, and zero federal refunds.
Sorry, I misread this above statement from your post. I read it as a flat income tax, but you said flat federal sales tax, which I take to mean that if the sales tax should ever be adopted instead of perhaps your prefered method, you would prefer no rebates be given back, because as you point out the opportunity for fraud. That is a good point.
As I pointed out in previous posts in regard to the sales tax, it can be made to be somewhat progressive by excluding the necessities for living, and only taxing what might be considered non-essentials. So if you consider food as the most basic necessity, I would propose that to be excluded, and that has already been shown to work very well in some states, as in Colorado where food is not subject to state sales tax. I believe restaurant food is subject to tax however, although I am not sure, but I would agree that eating out is non-essential, it is basically a luxury. Also shelter should be considered essential, but I think only up to a certain threshold, because we need not exclude tax on mansions and high dollar situations, those would be a luxury. Clothing is another necessity needing debate, but here again separating necessity from dressing in luxury would be difficult. I would propose the option of possibly excluding sales tax on used clothing, perhaps all used stuff purchased at second hand stores. Transportation, another knotty subject, but here again an exemption to a certain threshold could be considered.
Even though we begin to get the impression that exempting necessities in designing the sales tax system could become moderately problematic, I still think it would be much simpler and straightforward than the current income tax code that we have. And if done correctly, the poor could live virtually free of paying much sales tax by simply limiting their purchases to the necessities. If they insist upon buying junk that is non-essential, then they pay tax, but they should pay tax and help support the massive federal bureaucracy that they have helped create by voting the people into power that have built this monstrosity of a government. Also another point, we now use tax policy to socially engineer society, and that can still occur very effectively by encouraging the poor to buy less frivolously and more on essentials. Those that have the money will be happy to still buy the luxuries and discretionary products and services.