How Trump Could Be Blocked at the Convention

The New York Times has a good flowchart that explains how the process might work.

“Most states ‘bind’ their delegates to candidates based on primary results. But most delegates are released if no candidate wins a majority in an initial vote at the convention, so those who were bound to Mr. Trump could shift their support. This scenario is less likely if Mr. Trump is close to 1,237 delegates, or if he continues to face a split opposition.”