According to the Washington Post Democrats are reeling from the nomination battle by complaining about the structure of the United States Senate. The state system for composing the senate cannot be changed by amendment or otherwise.
On the other hand, if the incumbent president needed to win the plurality of votes cast in the nation to be reelected then you can believe that presidential appointments to the judiciary or indeed any job would be designed to appeal to the majority of the country. And it does not take a new constitutional convention or even an amendment to change the method of selecting the electors. Any state can do what it wants in this respect.
States Have All the Say on How They Use Their Electors