alt Hacker NewsBecause in states like California, Colorado, etc., vast swathes of Republicans do not bother to vote because their vote is overridden. The numbers don't work in reverse.
Just look at the county maps within blue states: these elections you speak of relied on those folks being entirely disenfranchised.
Of course it works in reverse. Plenty of Democrats are not going to bother to waste their time in California when the current electoral outcome is a foregone conclusion. Similar with Republicans in Mississippi.
If the rules changed to a popular vote where even "safe" states were up for grabs, I think there would be lots of previously uncounted "dark matter" voters who would activate and would significantly impact the outcome.