What advantages did the founding fathers see in electoral college that made them pick it over other potential voting systems?
I'll quote my answer from a related question:
When the Constitution was written in 1787, information traveled much more slowly than it does today, and the framers believed that most people would not be well-informed about issues and candidates outside of their own state. Consequently, rather than having people vote directly for the President, they instead had people vote for electors, who would be prominent, well-informed citizens of their respective states. The idea was that people would vote for electors whom they generally agreed with and would trust to make the right decision. Electors would then use their individual judgment in voting for President.
There are two other things that should also be noted:
- The Constitution doesn't actually say anything about how electors should be chosen. This is left to individual states, which can use any method they want—and they don't have to hold a general election. Early in the country's history, electors in the majority of states were chosen by vote of the state legislature, not by the people directly. Gradually, direct election became the norm.
- Under the Constitution, if no single candidate wins a majority of electoral votes, the President is chosen from among the top three candidates by vote of the House of Representatives. The framers did not anticipate the formation of a two-party system, so it may have been thought that this outcome would be typical rather than extraordinary. In that case, the Electoral College would have been a system for nominating presidential candidates, with the House actually choosing the President.
In short, the Electoral College was designed to balance the desire for a democratically elected executive with the distrust of the common people held by some of the framers.