Where exactly does the Constitution say that? What you are referring to is actually a SCOTUS case, Marbury v Madison, where the Marshall Court took judicial power for itself. (Rightly or wrongly, that case is an entirely different debate, which is ripe for abuse. For example, when the SCOTUS was going to declare the "New Deal" unconstitutional, FDR threatened to pack the court by adding more Justices to it, so that we would have 15 instead of the current 9. They caved)And that petty little bit about the Supreme Court being the final arbiter of what the Constitution means.
So, are you a "negative rights" person? That is, do you believe that the people and the states only have the rights that are enumerated in the COTUS? For if you read the "general welfare" clause to mean "redistribute wealth" then the 10th amendment becomes meaningless, as the government can twist "general welfare" and "interstate commerce" to mean anything it wants it to mean.It probably has something to do with that pesky "ensure the general welfare" bit that you seem to ignore.
The heads of the two political parties. They call the shots. Them and the big money supporters who fund them. There are really very few differences between the R's and the D's. Sure, they squeal loudly over what few differences there are, but when push comes to shove, they all follow the same path.Oligarchy ... Well, I suppose it can be seen that way, but I don't think so. Since this requires the rule of a privileged few, we would have to define that ruling class.

