Prior to arriving at the eventual wording of section 1 of Article II, the Constitutional Convention specifically voted against a number of different methods for selecting the President, including
? having state legislatures choose the President,
? having governors choose the President, and
? a national popular vote.
After these (and other) methods were debated and rejected, the Constitutional Convention decided to leave the entire matter to the states.
The constitution does not prohibit any of the methods that were debated and rejected. A majority of the states appointed their presidential electors using two of the rejected methods in the nation's first presidential election in 1789.