"Require... electoral votes to be allocated in proportion to the popular votes"

This quote by Robert A. Dahl is referring to the current system of electing the President of the United States. Under the present system, each state is designated a particular number of electoral votes based upon the number of representatives they have in Congress. These electoral votes are then cast in favor of the candidate who wins the popular vote in that state. Nevertheless, this quote is suggesting that the electoral votes ought to be designated in percentage to the popular votes, instead of the current system of winner-takes-all. This would mean that if a prospect won the popular vote in a state by a small margin, they would still receive a proportionate number of electoral votes, instead of all of the electoral votes from that state. This would ensure that the electoral votes more properly show the will of individuals, rather than the existing system which can lead to a candidate winning the popular vote however losing the election.