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.
In some states, delegates are elected directly on the ballot. In others, delegates are elected at a state convention or congressional district level meetings.
Rival campaigns and anti-Trump activists have already begun jockeying to fill low-level delegate slots in states that have already voted in order to get themselves elected to the national convention.
If they can infiltrate the delegation, they will likely be bound to vote for Trump on the first vote of the convention. But they can vote against him in making the rules and defect to another candidate if the convention is contested -- when a candidate fails to reach 1,237 delegates before the first ballot.
Emails obtained by ABC News show the Trump campaign calling on supporters in Michigan to watch for precinct-level delegates who may defect to a rival candidate during a contested convention.
“Are they a true Donald Trump supporter?” an email to supporters asks. “Many impostors that are actually aligned with the establishment will emerge from the woodwork and try to throw off the process.”
Another email to supporters and delegates details complicated parliamentary procedure strategies, even including how to topple the chair of the convention. It also instructs precinct-level delegates to record audio or video of their local conventions.
“If we are going to make credential claims, we must have proof and evidence," the email reads. "Do not be intimidated by a bully chair, you have every right to record the caucus.”
In at least one case, a woman who is set to represent Trump as a delegate at the convention, began as a critic of the campaign.
Nearby, Doug Hartmann Sr. got a call from the Trump campaign after buying a “Make America Great Again” hat from his online store. “Somebody called and asked if I would be interested in being a delegate to the convention for Trump. And I said yes.”
Now, Kozanecki and Hartmann are two of the 1,237 votes that the real estate mogul will need to win the Republican nomination in Cleveland this July.
In the days before the crucial winner-take-all states of Florida and Ohio, the Trump campaign launched the five-person task force to achieve that goal.
“The delegate process keeps you up at night -- defending your delegates, maintaining your delegates,” Bennett told ABC News.
The team, headed up by Senior Adviser Ed Brookover, says they are confident they will get well past the 1,237 threshold to win.
“We are not going to get outsmarted on the issue,” Bennett said, as rival campaigns deploy similar efforts to steal Trump delegates away.
The group huddles every day, consulting closely with the campaign’s legal advisers, ballot access team and state directors with heavy discussion focused on timelines and important deadlines along with deployment of resources on the ground. The group then has a weekly update call with top campaign leadership.
Almost eight in 10 delegate slots to the Republican convention have not yet been filled, although almost two-thirds of the delegates have now been alloted for candidates, according to an ABC News analysis.
Much of the team's discussion also centers around strategy towards a small number -- about 130 -- of unbound delegates who could push Trump across the finish line.
“If you are an unbound delegate, you are going to get to know Donald Trump. If we have to do this hand-to-hand we will do it hand-to-hand,” Bennett said. “In the end all these unbound delegates want to be with the winner. They want more money for their state party, they want the president to come visit their state – they are going to choose who it is they think is going to win.”
These delegates -- from places like North Dakota and Pennsylvania, as well as some delegates previously bound to candidates who have since dropped out of the race -- can vote however they want even on the first ballot. Getting Trump supporters into those slots is crucial, but also require an extensive ground game.
The campaign says they are flooding the zone with multiple emails and phone calls and if Trump is close enough to the nomination, more options remain on the table to seal the deal.
Multiple experts tell ABC News that no Republican National Committee rules prohibit political deal-making between campaigns and delegates on the floor of the GOP convention in Cleveland.
“There are no RNC rules which prohibit such transactions,” a rules expert told ABC News. “We may see some of the campaigns implement aggressive first ballot and multi-ballot strategies to peel off delegates.”
An Ohio state law on bribery may be the only restriction in play, given that delegates aren’t publicly elected officials.
“Since the First Amendment protects most of what we call politics, it would really be in a very narrow category of instances where bribery would be triggered,” another rules expert told ABC News. “Obviously in politics there’s horse-trading, and that’s not corruption.”
But as for Hartmann and Kozanecki, their minds are made up. “I am for Trump: first, third or hundredth ballot,” Hartmann says.