1. Disqualifying delegates
If Donald Trump narrowly crosses the threshold of 1,237 delegates he needs to clinch the nomination, the fight is still not over.

Campaigns and their allies are preparing to pepper delegates — and perhaps entire state delegations — with eligibility challenges meant to keep their rival’s supporters out of Cleveland. If Trump were to earn, say, 1,250 delegates, but an opponent were to successfully challenge the seating of South Carolina’s 50-delegate slate, Trump could find himself short of the magic number and facing a much murkier second ballot.