How big of a vote gap would it take for you to drop the Electoral College?

[BmorePat87]

A thought I had yesterday. With the continued population shifts, it is expected that 2/3rd's of the country will reside in 1/3rd of the states in the next few decades, giving incredible power to a small minority of the country. The President could be elected with 10 million less votes and a filibuster proof Senate majority could exist, representing only 30% of the nation. This would have implications for the Supreme Court, putting control of 2.5 branches in the hands of very few people.

Would one candidate having 5,000,000 less votes cause you to finally think that the Electoral College is not a good means of electing the President in the modern US? 10,000,000? 20,000,000? Or would you always be sold on this?