An independent contested the count in michigan, not hillary. Al Gore contested the 500 votes in Florida, under the law, and any sane contestant would do the same, especially with the shenanigans that happened in west Palm beach, which gave him the win, if it were not the butterfly ballot with his 10,000 or so votes, going to Buccanon by mistake.
Abrams, I'm uncertain about because it was a State election and I don't live in georgia.
But, okay....when valid, democrats contest elections, again WITHIN THE ELECTION RULES AND LAW....in the courts, before certification.