There is one factor not considered here. Hillary wins in 2016 and by 2020 there are 15-20 million new voters-new citizens primarily immigrants from the third world mostly arrived illegally. 12-15 million will vote for Hillary and every other Democrat running for office.
That is very true, and something that people are not thinking about. If the Democrats win this year, there will be a far smaller chance of them losing 4 years from now. The demographics are changing, and they are changing to the benefit of the Dems. Love it or hate it, that cannot be denied. We need to take all our victories NOW rather than wait for a later that may never come.