That's a great start, but it's only as valid as an activist judicial branch says it is. If congress passes a law that goes against the reading of that old parchment, someone brings a case that works its way to SCOTUS, then they vote based on the vacation they are provided, then the law is declared valid. If they decide it is not, then it is not. It doesn't matter what some armchair critic of the law thinks. They can tweet and tweet, they can blog and blog, they can vent on forums, but unless they become POTUS in a term where you get to sit 1/3 of the bench, you've got no real shot at changing it. Doesn't matter if you lean left or right, a single POTUS sitting 3 judges is rare enough to not consider it a real possibility. So an activist bench can cause disruption for decades/generations.