The Electoral College started as a way to boost the political power of smaller states, which was a major issue at the time of the founding, but ironically has evolved into a system that disenfranchises voters in both big and small states. Voters in big states like California, New York, and Texas are disenfranchised because it's a waste of time for candidates to spend any time visiting or addressing the needs of states that are 100% guaranteed to go Democrat or Republican. Small states like Wyoming and Vermont have it twice as bad, since not only are they 100% guaranteed to go one way, they also aren't worth hardly anything -- despite the "boost" they get from having their senators counted toward their electoral votes.
The only group of states which arguably benefits from the Electoral College system is swing states, especially big swing states. Voters in Ohio, Pennsylvania, and Florida enjoy unprecedented access to candidates and their key issues catered to even at the expense of the country as a whole (for example the issue of normalization of relations with Cuba, which was several decades overdue, has been stalled by parochial opposition in Florida).
Going to a popular vote would certainly boost civic engagement and voter turnout -- since everyone would feel like their vote "mattered." Yes, it would also increase the political clout of "big" states, but really, is that any worse than what we have now? Shouldn't presidential candidates have to fight for voters in places like California & Texas?