Cranky old man: Electoral College or Popular Vote
What I used to teach my 8th - 12th graders:
The Founding Fathers created the Electoral College for several reasons. First, they realized that the popular vote is a direct democracy, and they never intended the United States to be a direct democracy due to direct democracy's high failure rate--inability to accomplish governing, minimal majorities could tyrannyize those opposing them. The United States is a Constitutional Republic with failsafes to single dominance built in regardless the situation or the era, the Electoral College being one of the Constitutionally written failsafes. Another example, each state, regardless the population or lack thereof, possesses equal representation in the Senate. Population size is taken in to consideration in the House of Representatives. The Founding Fathers understood that not everyone or every state was equal, discounting a state's size in both landmass and population, was counterproductive and harkened back to governing with a lack of representation; they were really afraid of tyranny. They understood that some elections were going to be wildly popular, think Ronald Reagan's landslide 1984 win, and wildly unpopular, think Tuesday, so they did not take the Electoral College lightly, especially since to eliminate the Electoral College means there must be BOTH a supermajority of both houses AND the approval of 38 states.
The Presidential Election is a two-part process--November is the first part and is purely democratic and December is the second part where the 538 Electoral College electors cast their votes.
The Electoral College ensures that many types of voters, campaigning, AND coalition building, i.e. different groups coming together as one, have a voice. Literally, without the Electoral College, California, Texas, Florida, New York, and Pennsylvania, because they have eight of the ten largest cities in the U.S., could elect the president. Therefore, Montana, Maine, Maryland, and Nevada become unimportant to the candidates. However, city dwellers are just one type of voter and don't represent the country, just as if a candidate were to win the South, the Northeast, or win the Midwest. Those areas reflect a region, and a candidate cannot become president because they won a region, thanks to the Electoral College.
Swing States, because they change from election to election, also are important, but again, not the only focus, because of the Electoral College. They are a failsafe to voter fraud, as a candidate has to predict which states will be the key states to manipulate votes. As we have seen, predicting is not easy to do. Swing States keep political parties from ignoring states, for example, George W. Bush's flipping West Virginia, from a traditionally Democrat state to a Republican state, is what ultimately won him the election against Al Gore.
While George Washington saw no political parties and implored the country to avoid them, out of respect, politicians, who had already become divisive prior to Washington's presidency, chose to not align themselves with one party or another during Washington's presidency. They agreed that Britain's tyranny of the colonies needed to end; how to keep that tyranny in-check and at bay was not a single-thought process but a divisive one. The Electoral College ensures there is diverse representation and a checks-and-balances in the election.
The Electoral College is chosen in a two-part process with the first phase occurring prior to the November, General Election. The political parties control the first part, with each party selecting their allotted number of electorates--California has 55, so the Democrats select 55 electorates and the Republicans select 55 electorates--and the rules governing the state's choosing process is a State's right issue. The second phase occurs on the November Election Day. If the popular vote went to the Democrats, then the state's Electoral College electorates are those chosen by the Democrats. California's 55 votes go to the Democrat, i.e. Hillary Clinton. Maine and Nebraska split their electorate votes whereas the other 48 are an all-or-nothing entity, because that is how the individual states chose to write their rules governing their electoral college.