Bush is either insane or a liar. Every addition to the federal bureaucracy makes the executive stronger. Most legislation never crosses the legislative branch; most laws are imposed as "regulations". Except for a few minor "oversight" functions, Congress has gained nothing over the executive in living memory.
Now here's an interesting point: it has to be like that if power is centralized. It means there are more federal laws. Congress can only pass so many, since the whole House and whole Senate has to pass every new law. But the executive can delegate each policy area to a different department to write the regulations for that area. The sheer volumn forces a shift to the executive. The president really isn't that powerful; there's no way he or anyone can really keep track of all of it. That's very dangerous. Power in America has always been divided and spread around, but before it was by the federal system and checks and balances, which kept people accountable. Now it's spread throughout a bureaucracy and no one's accountable.
He's not insane.