The only benefit of a sales tax as I see it is that you get a lot of money out of tourists from foriegn countries, thus reducing the total tax burden on Americans. Other than that, not a fan, it can be regressive, and it will stifle spending, and discourages business (and getting money of tourists would help crush the tourism industry)
How does it discourage business?
When you hear complaints about companies setting up a PO Box on some Carribeian island, remember they did so to avoid some of the onerous income taxes put on them. Such as paying income tax on foreign revenue. Offshore headquarters at a PO Box will no longer have a tax benefit and will no longer happen.
Also, currently there is better than $10 TRILLION of American wealth in offshore financial institutions, primarily because of the tax system and level of taxes. With the removal of the income tax and other federal taxes, a very large portion of that $10 TRILLION will return to America and move through our economy.