The Doctrine of Separation of powers sets up three branches of government to help balance the powers of the government. Each branch has its own powers that allows them to check the other branches. In the United States we often think of each branch as its own distinct institution with its own separate powers, but that is not really true. Many powers are shared by all of the branches like making laws for example. We typically think that it is the legislative branches job to make laws and the executives job to enforce them. But, in reality all three branches can do it. The judicial branch can do through their rulings in cases. Therefore, the lines can become blurred when it comes to who has what powers and that is were limitations are needed.
The Supreme Court has issued many rulings that both limit the powers of the legislative and executive branches. But, also help balance the power between all three of the branches. Limits usually come out when one of the branches tries to use an inherent or implied power not explicitly written in the constitution.
We can look at two examples where limits were put on powers created for the legislative and executive branch. The first is when President Clinton presented the Line Item Veto Act to congress, which congress passed. This would allow the president to veto one line out of a bill instead of vetoing an entire bill that may be a good legislation. The Courts heard this in Clinton v. City of New York and ruled that this was indeed unconstitutional. The majority said that the veto power was a very specific process outlined in the constitution and striking out parts of legislation violates that veto power. This Act was attempting to amend the constitution through law. An alternative for the president then, is to issue a signing statement along with the law that is basically a presidential note on the legislation.
The other example is the legislative veto, which can be used to veto a law that the executive created with power that congress gave to it. These vetoes exist because they are placed into laws which delegate power to the executive branch. in INS v. Chadha the Supreme Court also ruled that this veto power was unconstitutional, under similar grounds of Clinton v City of New York. The veto process as outlined in the constitution does not list the legislative veto as a power and therefore, it is unconstitutional. These are just two easy examples to understand of how the Judicial branch has limited the powers of the other two branches. Which is its job to maintain a balance of power between all three of the branches.
It is obvious that our government is a lot more complicated than just three branches all separate with their own powers. I believe that when the branches share power and create new powers they are truly carrying out their job to the fullest. I can not imagine what the government would look like if each branch only stayed strictly within the narrow lines of their enumerated powers.