It isn't even necessary to make such massive eliminations. We had a surplus during Clinton's term. Just to put in perspective what you are suggesting, here is a short list of government items that are "not specifically authorized by the Constitution":<quoted text>
If we eliminated every federal department and function not specifically authorized by the Constitution, we would have a huge surplus at current taxation rates.
The United States Marine Corps
The United States Air Force
All Cabinet Departments (Departments of State, Defense, Treasury, etc.)
Well, you get the idea.