When we look at the structure of government, we all must realize that it is not about some idealistic set of principles, it is about mutual or common interest. Balance of powers is just that -- a balance of the interests of the powerful against each other in a manner that no one of them can gain dominance. Otherwise, there develops a dominant ruling entity -- whether it be a king, autocracy, plutocracy, or whatever.
The U.S. system was designed for a balance of powers -- Executive vs. Legislative vs. Judiciary. In theory it is a great design although in practice it is in constant search of balance.
There is one piece of the balance of powers that is little discussed -- or at least has been examined very little since the Civil War. That is the balance of power between the states and the federal government. Until that relationship is returned to balance, we will continue to see the growth of government at the federal level at the expense of the states. The states must come together in mutual self-interest to preserve that power. The Constitution has a provision for that, it is the power to amend. I don't think the Constitution needs amending. I do think that the states must elect members of Congress who will vote to return that balance. Or, better yet, let's see a President who will push to return that balance. There are a few potential candidates out there.