Actually, SCOTUS has nothing to do with it. The fact that they usurped the power in Marbury v Madison does not mean the power was ever actually theirs.
The tenth amendment says: The powers not delegated to the Federal government, nor prohibited by it to the states, is reserved to the states, respectively, or to the people.
Thus, the states can nullify any law they deem unconstitutional, the states can interpret the constitution, and the Federal government does indeed have to find ad verbatim permission in the Constitution to do anything it wants to do.
You don't realize the reprecussions of what you are suggesting should a truly belligerent congress/president ever get elected. Your system might sound all good and dandy when it comes to welfare programs, health insurance, disaster relief, exc. but by giving the government a blank check you are essentially saying if Obama passed a law tomorrow saying all Muslims can be killed on the spot that would actually be a constitutional law until the Supreme Court managed to organize and strike it down.
The reprecussions of "Congress can do whatever it wants" are more horrifying than you realize.
News flash: "My system" is not my system, it's how our government works.
The Supreme Court decides whether things are or are not unconstitutional, and is the one court in the land that overrides state Courts.
Why? Because it's the.... Supreme.... Court.
Things are not unconstitutional because Ron Paul.
These are facts.
Now, when I present you the facts, and you huff about what would happen if the government were controlled by, let's say, Nazis, that's besides the point.
If the whole government were full of evil genocidal maniacs on a power trip, then nothing that's written in any law anywhere is going to stop them. Duh.
Spouting hypothetical zombie commie nazi apocalypse scenarios doesn't alter the fact that the government operates a certain way.
Congress writes the laws. Laws go into effect. States must follow the law, or challenge it. The challenge goes to the courts. The decisions of those courts can be appealed all the way to the.... Supreme Court.
And then the Supreme Court renders its final judgment on the matter, and that ends it.
Until, at such time, the Supreme Court decides to take the matter on again, and reverse its own judgment. But nothing overrides the Supreme Court. Not lower courts, not Congress, not the President, not the army, and not wackjobs living in fantasy land 24/7.
If you don't like the way the government works that's fine. Seek to change it. Try to amend the Constitution so that things go the way you want it to.
Until then, you can either deal with reality, which is that the Supreme Court ultimately settles matters of Constitutional law, or you can ignore reality.
What you decide is your choice. I live in the real world.