I don't necessarily know if looking at the Clinton Administration would be useful as previously suggested because he became president at the conclusion of the Cold War and the United States simply didn't need the expensive and costly military expenses anymore. Resulting in combination with that, and a slight tax increase, President Clinton was able to balance the budget; however, the debt to GDP ratio was lower under President George W Bush, which is a better indicator than just yearly deficits because it measures growth.
The President, when deciding to cut spending, looks at a wide variety of options:
The GAO or General Accountability Office audits public spending, and the waste that the GAO exposes can be cut.
You see, it is very difficult to cut spending because it is the same thing as a tax increase. To wit, a dollar spent is a dollar earned. Even though there was spending on something as ridiculous as research on mice in Oregon, it gives those scientists and researchers funding and employment.
45% of the budget goes toward entitlement spending; 19% goes toward defense spending; TARP 4%; etc.
Basically, the President has one option: to cut discretionary spending. Discretionary spending is what the President and the Congress decide to spend through annual appropriations (spending) bills. Examples include: foreign aid, Coast Guard, FBI activities, infrastructure, interior, housing, education etc. (clearly, all of these "non-mandatory" spending is pretty important)
. The President cannot cut non-discretionary spending which is mandatory. Examples of this spending are: Social Security and Medicare.
This is why it is very hard to cut the budget. Interestingly enough, estimates from the CBO say that eliminating earmarks in their entirety would equate to a savings of only $10 billion. Regardless, I'll take it because it would definitely lead a drive to a smaller, less costly and more accountable government which would better serve the people by saving us tax dollars.
There is also another interesting point of view to consider: just cutting the budget. By doing this it forces the government to be extremely efficient. For example, if I had a large pile of candy and someone takes a piece, who would notice? However, if I only had five pieces of candy and someone took one, then we would find the waste and fraud and the government could not operate if business was carried out like the current establishment.
I don't know but it's interesting to research and discuss.
PS: for further research on President Obama's proposals check out this link. From a preliminary observation, it will be nearly impossible to reach those goals without a significant spending cut and a tax increase: