The Electoral College
Everything in the way the US government is organized is a compromise. From the two chambers of the US legislature, to the Bill Of Rights, to the Electoral College, literally every sentence in our founding documents is a compromise between competing interests (that is a thing that Americans used to be able to do).
The Electoral College was a compromise which was appropriate for its time. In the 1700s, the federal government was weak, the President was little more than a figurehead, and the states were de facto each an individual country.
The question we should ask today is, does the Electoral College do more good than harm for the 21st century USA? It clearly disenfranchises people. The votes of millions of California Republicans, for example, mean absolutely nothing in a Presidential election. They may as well not even be counted. Is that the way things should be?