The president has many powers that we are unaware of. Most of those powers may even go unused or be misused. For example, signing statements are something I didn't even know existed until I started this assignment. A signing statement is a written comment issued by the president when any new legislation is passed.
The powers that the presidents are given can very easily be abused. Mr. Bush used the power of a signing statement for much more than it's purpose. In the article Read the Fine Print it mentions exactly that. "Part of a strategy to expand presidential powers at the expense of Congress and the courts. His signing statements have become notices to Congress that he simply does not intend to follow the law, especially any attempt to hold him accountable for his actions." Bush used signing statements while attempting to destroy the Separation of powers and just focus on his needs and wants.
However, a signing statement can also be used for the good of things. Most presidents use signing statements to get legal obligations on the record for judges to consider in a court challenge. It may not mean much when it first starts out but it's similar to that of the snowball effect. As time goes on the president will keep adding more and more to it and it will eventually become significant.
Depending on the president the use of signing statements can go two completely different ways and if you look back in history that is very evident.