But it also indicates that in a close election, the outcome may be in doubt for up to a month. Citizens left out Under the Electoral College system, only U.S. citizens who are residents of a state may vote for presidential electors, because it is the states, not the citizens, who elect the president. The number of people affected is significant. Puerto Rico alone has over 3 million people. Each state sets its own procedure for selecting electors.
Party conventions are the most common method, but there are many other variations.