Here is a little from a quick Google search. Keep in mind at the time of the Constitution news traveled slowly between states and most people knew little of the leaders outside their own state:
A third idea was to have the president elected by a direct popular vote. Direct election was rejected not because the Framers of the Constitution doubted public intelligence but rather because they feared that without sufficient information about candidates from outside their State, people would naturally vote for a "favorite son" from their own State or region. At worst, no president would emerge with a popular majority sufficient to govern the whole country. At best, the choice of president would always be decided by the largest, most populous States with little regard for the smaller ones.
I do, however favor an election based on the popular vote.