Separation of Powers and Checks and Balances
This is a great excerpt from Federalist 51 by James Madison. Just as a reminder, the Federalist Papers, which were written by Hamilton, Madison, and John Jay, were an attempt to get the Constitution passed, to get it ratified. So these were really kind of op-eds that they were publishing to convince people.
But this is a great passage: "If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary." In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed and, in the next place, oblige it to control itself.
It goes on to talk about how we can keep government from becoming too powerful by so contriving the interior structure of the government as that its several constituent parts may, by their mutual relations, be the means of keeping each other in their proper places. Remember, this was in defense of the Constitution. So arguably, this was in place that somehow this Constitution had contrived an interior structure so that the several constituent parts of government, by their mutual relations, would keep each other in their proper places or you could even say keep each other in check.
So, in line with this passage, there are really two big ideas embedded in the Constitution as to how our government is structured. The first is this notion of separation of powers. We have three branches of government: you have your executive, headed by the president; you have your legislative branch, which is Congress; and you have your judicial branch, which is the U.S. Supreme Court.
This notion of separation of powers means that you have these fairly independent branches of government. The idea was to make them reasonably independent so that one group, one branch, could not take over the others. The legislative branch, Congress, is charged with budget and they're charged with creating and passing laws. The executive branch, headed by the president, is supposed to execute, run the government based on the laws that Congress passes.
You have the judicial branch that would decide whether things, say laws that Congress is passing or actions that the executive is taking, are constitutional or they can interpret laws. So these different powers are put into these different branches; the powers are separate.
Now, related to that is another very powerful idea, and this is keeping each other in their proper places. This is the idea of checks and balances. Each of these can't do whatever they want; they're all balancing each other. They all have checks on each other. For example, the executive can veto the legislative branch, which can veto a law passed by Congress, but then the legislative branch can override that veto.
The legislative branch controls the budget, so it's not like the president or the executive can do whatever they want or that they can just spend as much money as they want. The judicial branch, in both cases, can be a check, and they're saying, "Hey, you're doing something that is unconstitutional," or "We're going to interpret the laws that the legislature has passed."
The executive appoints the judicial, but even there, you have to get congressional buy-in. Once again, you have these independent branches of government; all the power isn't in one, and they are interdependent. They provide checks and balances on each other, and this is all about what Federalist 51 is talking about. So that by their mutual relations, they are the means of keeping each other in their proper places.