Why is there both a judge and a ballot box in your analogy? In the primaries, there were only ballot boxes, and Clinton got almost 30% more ballots from normal people outside of the DNC than Sanders. It was a landslide so large that the media had to construct a horse race story just to try to keep it interesting.

The DNC had "groomed" Clinton insofar as she had run in the primaries before and was familiar with the rules. She didn't receive any special treatment from the DNC during the primaries as far as their emails showed.