I'm not good at math, but according to this article, there were well over 200 million US voters--REGISTERED to vote. As it points out, when Bill Clinton won, there weren't 200 million who were even eligible to vote.
http://www.truth-out.org/news/item/38290-us-voter-registration-is-highest-in-history-but-what-about-turnout

Yet the total ballots counted (true, an estimate) is 128,843,000

So while turnout and registration were better than usual, there were still MORE non-voters than voters for either candidate. What would results have been if the other 75 million had voted?