Without the president, separation of powers would be much weaker. There would either have to be an executive council (which would be ineffective) or have the legislature decide all executive matters. None of these are practical. A singular leader of the executive branch allows a broader agenda, easier affairs overseas, and a good counterbalance to the legislative and judicial branches.
There is a need for someone to take the responsibility of the government and to justify its actions toward the world. Without a president, there would be a severe lack in communication between countries as the government entity will not necessarily have a spokesman. The president acts as this spokesman.
Although the president of the United States is often referred to as "the most powerful man on earth", it is just a misconception. Even though there is a president, Congress still makes most of the calls.
Here are a few things a president is good for:
1. Foreign minister. A country needs a figure head and a face to present to the world, no matter how democratic you are.
2. Boost morale and patriotism for a country in a time of need. Look at George Bush's ratings after 9/11.
3. Lead in a time of war. By the time Congress makes a decision, the war would be over. And the U.S. Would be the one in ruins.
4. Triple balance. Executive, Legislative, Judicial. 3 branches is not to much at all.
If yo are just making this because you hate Obama,please get lost.
Countries consistently boast a "for the people, by the people" philosophy and never use it in a proper manner; if the people already have it under control, why create a manipulative (and like-wise manipulated) figurehead that is sure to cause trouble in a number of scenarios?
It is entirely unnecessary and redundant.
I believe no man/woman should be able to raise themselves above others, and the president that is elected is not always what the majority of what the people want. There are complications with voting and I think the goverment should be able to run the country smoothly without the president. I also think the bigger decisions that effect the entire USA should be able to be made by the people, who know what they want.