The Electoral College has failed for the fifth time, and twice in 16 years.
The same thing happened in 2000, with Al Gore, and in 1888 with Grover Cleveland, and in 1876 with Samuel Tilden, and in 1824 with Andrew Jackson.
Each of these four times, and now with Hillary Clinton, the Democratic nominee won the popular vote, but lost the electoral vote to their opponent, with each candidate who won the Presidency, except John Quincy Adams in 1824 (National Republican) being a Republican–Rutherford B. Hayes in 1876, Benjamin Harrison in 1888, George W. Bush in 2000, and now Donald Trump in 2016.
To imagine it would happen 16 years apart (2000 and 2016) after having occurred 12 years apart (1876 and 1888) makes the urgency to change the Electoral College, but it has been attempted before and has failed.
So we are stuck with the reality that this can happen again and again, sadly!