There were several. But this biggest, I think, was:
The American party process….The New York state GOP by-passed the primary process, and got slammed for it. A third party candidate rose to the mainstream. Energized voters forced the hand of party leaders. All positive signs of health, I think; the more third parties we have, the more responsive party leaders are obliged to be, the more people pay attention to political primaries, the better for American democracy.
More here, if you’re interested.