The biggest different between VAT and Fair Tax is that a VAT would just be another turd on the pile of crap that is our tax code. The Fair Tax, AT LEAST, makes the number of people that would be potential criminals for trying to work and earn a living WAY down; Fair Tax repeals the income tax.
And as long as we are talking about sobering reality, I heard some unfortunate news that I can not dispute. The Constitution is dead... and as much as it is not dead it is simply meaningless. Thomas Woods and Kevin Gutzman make a strong argument that the Constitution was on its way out the door with the Wilson administration and the philosophy of Oliver Holmes. The Constitution today is like British nobility: It is an interesting piece of history and a symbol of our cultural heritage, but other than that it has absolutely no force of law. The Constitution was a contract between the states for mutual self interest for which the federal government is an agent, and anyone that believes that is utterly delusional. Today we have much more a democratic republic, not constitutional federalism.
Many people today, to me, seem to think that kings and dictators are bad because they are evil, greedy, and selfish rather than finding the philosophical superiority in self governance.
Today the freedom many people desire is the freedom from responsibility. It only further breaks my heart that these people get away with calling themselves "liberals", for which they are anything but.
Today we have a compassionate, but none the less absolute, tyranny. The fact that government does not exceed anything greater than its own desire for control is no limit at all. It just means they are nice... except when they are not. We also find it acceptable because remember the other problem with kings is that we didn't vote for them. If we could just vote for our king, then everything would be fine, right?
btw, this isn't blaming anyone in particular, just pointing out the end result.
So basically, there is no question of constitutionality because there is no Constitution.
I am curious what is going to be the result of the April 9th Article V summit in Washington DC. The hosts have some great suggestions, not to mention some good ideas from state legislatures on how states can protect themselves (for which naming would go beyond the scope of this comment).
But remember, any amendment will still only be a symbol on an already dead symbol. An amendment would only be a formality for the real process of fortification (protect citizens from being individually attacked by the fed; take a look at what Montana and Arizona are doing) and nullification (reject federal authority).
Anything less and all the amendments you pass are just make a bigger constitution to wipe your tears with.