I live in Washington State, which was essentially totally ignored by all the candidates. The reason is simple - WA is an overwhelmingly blue state with a winner-take-all delegate selection.

If elections were based on the popular vote, then the candidates would have been here campaigning, which might have dramatically changed the vote in WA. Not enough to turn it red, but a big chunk.

My point is that changing the rules on how Presidents are elected will change how they are campaigned, the platforms of the candidates, etc. One cannot assume a voter tally under one scheme will be the same as the tally under another - not at all.