This explains what happened--and the Russians weren't responsible
I was curious since the popular vote doesn't really matter in Presidential Elections (after all Clinton won that with one of the largest percentages in a US election). The Electoral College is the real decider with only 270 electoral votes needed to win. So, I went to 270toWin to play with their interactive Electoral Vote map.
First off, there are 2,250,000,000,000,000 possible outcomes with the Electoral College system! (Long explanation on that), but it didn't take too many states to flip for Trump to have won. That means it was a real gamble to run a candidate as unpopular as Clinton since there were no guarantees that New Hampshire, Nevada or Virginia wouldn't have voted for Trump. Or that Michigan, Pennsylvania, or Wisconsin would vote for Clinton.
There were four states, New Hampshire, Michigan, Pennsylvania, and Wisconsin which were all decided by less than 1% in 2016, with Michigan the closest. That state was won by about .23% - that’s only 2,300 votes per one million votes cast. Donald Trump won three of these four states, none of which had been won by a Republican in a generation. Those 46 electoral votes put him across the 270 he needed to win. Interestingly, despite a fairly competitive election, only four states were decided by 5% or less in 2012; that number grew to 11 in 2016. Only Florida was decided by less than 1%.
The thing is that winning any of one of those four states would mean Trump would be President. Or that Trump's electoral college win could have been much higher! Remember the popular vote has no relation to the Electoral College numbers. All one needs is to get the largest number of votes to get ALL the Electoral College votes in most states.
There would still be a possibility that Trump could have been president even if all four of those states have voted for Clinton. That is because the Electoral College result would have been a tie (269-269). That means the election would be sent to the House of Representatives with each state delegation getting one vote (a similar activity takes place on the Senate side to pick the Vice-President). In the case of a tie, the election for President is decided in the House of Representatives, with each state delegation having one vote. A majority of states (26) is needed to win. Senators would elect the Vice-President, with each Senator having a vote. A majority of Senators (51) is needed to win.
It would have been highly likely in the case of a tie that the election would remain undecided after the Electors voted. That means Congress would meet in joint session on the first day in January to count the electoral votes (this count happens whether the election is close or not). If no candidate has reached 270 Electoral Votes, then the House and Senate take over and elect the President and Vice-President, respectively.
It seems likely Trump would have been president given the current US legislature is solidly Republican had there been a tie.
Toss in it is possible to win the Electoral College with only 11 States (California, Texas, New York, Florida, Illinois, Pennsylvania, Ohio, Michigan, Georgia, North Carolina and New Jersey). However, nobody has been elected President since 1900 by winning fewer than 23 states. (Take the quiz at 270towin to see where I got these figures)
Anyway, While the democratic party is responsible for picking a loser like Clinton, it seems to be more that the anti-democratic nature of the US elections needs to be addressed. After all, the only way the Russians could have influenced the US presidential election would be to have somehow created the Electoral College since that is what really put Trump in office.
See also: Why Trump Had an Edge in the Electoral College
Five myths about the electoral college