I think proportional distribution was the norm prior to 1960. Not only does it return us to the purpose of the ec, it is a firewall against “spigot cities”. Dem fraud can only steal districts they already control.
Proportional distribution was never the norm, as states traditionally saw concentrating their EVs as the way to exert the most influence.
I suspect that any measures actually to do this in “swing” states will face aggressive judicial challenge on civil rights grounds. The Democrats batted close to 1.000 in those challenges (against early voting and voter ID) last year, so no reason to doubt their success this time. These measures would “work” for their Republican sponsors only because they would effectively dilute geographically concentrated minority votes (and can only be enacted by Republican legislative majorities elected in the same diluting fashion), and signed by Governors elected in low-minority-participation non-Presidential elections.
Proportional distribution of electoral votes?
I don’t know of any state ever doing it that way. That’s a pretty modern idea.