I'm sure that's how it would go. It would be a major hurtle toward eliminating the IRS and promoting a national sales tax at some point in the future.
I still have a problem with national sales tax over income tax as a revenue model.
This past six month period would be a really good example. Folks have their "income" factored into their spending habits, whether it is withdrawn or VAT. Now, when you have a set of events like we have had over the last year, where consumer confidence drops to record lows and sales of EVERYTHING drop to the basement, governments are then looking at harsh revenue shortfalls for which they are not able to plan.
Straight withdrawal income tax, as much as we don't like it is a much easier system for both sides to plan cash flow. It also keeps state and local governments out of that added pool of cash that is not withdrawn.
Look at all the different VAT, municipal, regional and National taxes that the different European models have, several starting with "just a National Sales Tax". They now pay more than 60% in total.
So besides repealing the 16th Amendment and maybe Article 1 sec 9 "No Tax or Duty shall be laid on Articles exported from any State." I see it as a very interesting exercise.