Most people don't really understand what form of government we actually have in the United States of America. Generally, people falsely declare this country as being a democracy. But, in a true democracy, the people govern themselves. Each and every decision in a democracy is voted on and decided by a popular vote. Could you imagine having an general election for every law and policy that is made in this country? For that reason, we are a "form" of democracy called a republic. In a republic, we elect representatives to speak and vote for us.
Further, we are a collection of States with each State having primary control over its own citizenry. Collectively, those States have "agreed" to be part of a "union" or what can also be known as a federation of States. We clearly represent this fact in the "star field" of our American Flag. This federation or federal system of government provides for any laws and policies that are of common interest to all of the States in the union. As part of joining the "union," each state agrees to abide by the greater laws of the federation. A typical example of what a federation hopes to achieve is a single, standing military which would be stronger and more protective than any haphazard collection of militias by each of the individual States in that union.
Now, the purpose of all the above verbiage is to try and give you the rationale as to why we have an electoral college. It all comes down to the concept of individual State's rights. The electoral college is a mechanism by which each state, state by state, can decide on who will be elected as our next president. After all, the office of president is the only elected office in the entire United States government that "isn't" voted on by the electorate within each individual state and, then, sent on to Washington, D.C. Both U.S. Senators and U.S. Representatives are exclusively sent to Washington by state elections. But, not the President.
One by one, each individual State decides on its choice for President by awarding all of its allotted electoral votes to the candidate that gets the majority. That's how we wind up with today's concept of red and blue states for Republican versus Democrat. This is also an extension of the concept of a "republic" by using electoral votes to be representative of the population in each state. Could we elect a President by popular vote and not by an electoral college? Sure, we could. However, the States would lose a little more power in doing so. To be true to both our federal form of government and our republic, the electoral vote system should be retained. That's just my opinion.
Image by Thomas Hawk's photostream on Flickr with Creative Commons Licensing remix/adapt/modify permission (Click to View Other Works). Specifically modified by Cranky George for this blog entry.