Even if one candidate has more delegates than the other, that’s only a “plurality,” not a majority, per party rules. Candidates who earned delegates, but have since dropped out of the race, can try to push their delegates onto another candidate. A candidate needs to earn 2,375 delegates on subsequent ballots to win the nomination. However, having a contested convention is something the Democratic National Committee will do its best to avoid in the coming months. The last time a contested convention occurred was in 1952.