Guys, let me paint you a picture with words...
At the end of the primaries, both parties announce their candidates. Hillary Clinton beat out Sanders by such a small margin that experts are saying it was the coin toss that decided it. Somehow Cruz pulls ahead of Trump and wins the nomination. In the face of defeat, Trump announces he is creating a new political party called "The Trump Party" with their mission statement of "Make America Great Again" and he will be running for President under this party. Sander's realizing that now is his chance, decides to run as an Independent.
Suddenly America has four popular candidates running for President basically eliminating the two-party system. It wouldn't even matter who wins, our political system would see a much needed change and hopefully the break of the two-party system would last to the next election.
One can dream, but of course this won't happen, because this is America.