Answer: to create a buffer between population and the selection of a President.
The founding fathers were afraid about the possibility of a tyrant becoming president. They believed that the chances of this happening increased without an electoral college. The electoral college was supposed to create a buffer zone between the voters and the President. Without it, the candidate who wanted to be President would be able to manipulate people into voting for him easily, as people do not tend to make the right choices when it comes to politics.