Why we need the Electoral College

Because you and I and the courts and the politicians can all be expected to count to 270 and get close to the same result.

None of us can reasonably be expected to count 120,000,000 anythings with absolute precision.

If the election is really close, the country is better off with a stable and predictable result. A full nation-wide recount would be a disaster. Think of the Florida debacle, but everywhere at once.

The current model means that precision in counting is only needed in the places where the vote will be close (which is far fewer places than all of the states). It also means that there is no value to voter fraud is a completely red or blue state because once the electoral votes for that state are set, changing the majority has no effect.

If we had a nationwide popular vote, then vote padding (think of the Chicago machine politics and "vote early and often") would actually have meaning and vote fraud is easier where the outcome isn't in question.

Would I change anything? Yes, since the Electoral College votes are based on Senate and House representation, I'd have the 435 votes based on congressional delegation districts counted by the majority in that district rather than the count in the state as a whole. That would increase the chances of a politician visiting California (for example) where the state is "Blue", but not all of the districts are, because it means that all of the congressional districts that are "in play" for the House are probably also "in play" for the Presidential election.

Would a district apportioned Electoral College have changed any of the elections? I've not seen any research.

What is needed to make the change in a state from "winner take all" to a "winner by district" apportionment of Electoral College votes? This is a state issue and not part of the federal constitution (I believe) so it could happen one state at a time. Aren't there one or two that do that now?