Except that the rich or even moderately well-off never convert even close to all their money into something tangible while the poor almost always must immediate

Except that the rich or even moderately well-off never convert even close to all their money into something tangible while the poor almost always must immediately. The rich don't live paycheck to paycheck. They save, invest, go on vacation, etc. They defer the second taxation (sales/use) to a later date or place -- they have choices where the poor do not. So while it might seem flat theoretically, it becomes regressive quickly. But we probably agree on more than we disagree. I actually agree that flat isn't fair and that the current situation isn't fair to b&m stores either. I just don't think the solution is to interfere with interstate commerce. States need to enforce use taxes, or if that turns out to be unenforceable, which I suspect it might, rethink their taxation strategy. By the way, not sure why you were downvoted. I upvoted to correct that. Thanks for the discussion -- it got me thinking about this situation quite a bit.