VitalSigns posted:

Historical reasons, slavery mainly. The slave states feared a popularly elected president because the votes of free blacks in the North would count, while the massive Southern slave populations would not. By apportioning electoral votes to the states they could inflate the Southern
vote by (as it turned out) 3/5ths of the number of slaves.

It has persisted because the constitution was deliberately made quite difficult to change, and states that benefit from the EC system have their influence over constitutional amendments increased as well, also it almost never matters so people against the system don't have much motivation for the fight.