Part of the battle has come in the form of emails to delegates and supporters trying to lock down crucial votes. The other half is a five-person task force that has been quietly trying to amass the 1,237 votes needed.

"You try to learn as much as you can about everybody and figure out what makes them tick, what it is they think is important," Barry Bennett, a Trump Senior Adviser, told ABC's Chief White House Correspondent Jonathan Karl and ABC's Political Director Rick Klein on ABC's Powerhouse Politics podcast.

"We make sure of their 'woo-ability.' If they can be wooed they are going to get wooed and they are going to get to know Donald Trump," he said.

Candidates accumulate their delegate count based on the primary or caucus vote, but the processes by which the actual human beings are chosen to fill these delegate slots take place much later and vary by state.