Now, a presidential candidate could lose despite winning 78%+ of the popular vote and 39 states.

With the current state-by-state winner-take-all system of awarding electoral votes (not mentioned in the U.S. Constitution, but later enacted by 48 states), it could only take winning a bare plurality of popular votes in only the 11 most populous states, containing 56% of the population of the United States, for a candidate to win the Presidency with less than 22% of the nation's votes!