Is Donald Trump as good at making deals as he says? He’d better be or his chances of winning the Republican presidential nomination are likely to vanish before his eyes.

Absent a miracle, the primary season will end on June 7 with Trump short of the 1,237 delegates needed for a majority. To win the nomination on the first ballot at the GOP convention, he'll have to recruit more delegates. At the moment, we don't know how many, but maybe as few as 52 (the rough estimate of The Weekly Standard's John McCormack) or somewhere north of 100 if Trump loses badly in the California primary.

There are two places to find available delegates. One is the group of around 150 who will be "unbound" and thus free to vote for whomever they prefer. The other is the collection of delegates committed to a candidate no longer in the race. The most important bloc is Marco Rubio's, with 171 delegates.

Trump will have to negotiate no matter where he stands. The closer he is to 1,237, the stronger his position in seeking additional delegates. At some point, he may be seen as the party's presumptive nominee, as unpleasant as that will sound to his opponents.

Whatever the case, Trump will be brimming with bravado, which he defines in his book The Art of the Deal as "truthful hyperbole." It's part of his strategy for selling himself and his ideas. "I know about deal-making," he said in his speech to AIPAC in March. "That's what I do." And what's needed in Washington, he said in the Republican debate in Miami, are "people who can make deals."

If Trump is short of a majority by 100 or fewer delegates, he can go after unpledged delegates one-on-one or in small groups. He can't say that he would give them a job in his administration if he's president. That would be illegal. But there's a lot he can dangle in front of them.

President Ford's campaign in 1976 wrote the book on this. He invited unpledged delegates from New York to a glamorous state dinner held in the White House for Queen Elizabeth. It worked. Along this line, Trump could say he'd like to invite delegates as his personal guests to a weekend at Mar-a-Lago, his club in Palm Beach.

If Trump's overall delegate count is less than 1,100, he'll have to take more drastic action. He'll need to tap into delegates committed to Rubio or Kasich. Trump has already mentioned both, along with Wisconsin governor Scott Walker, as possible vice presidential running mates. That may help, but his prospects of gaining the support of Rubio's or Kasich's delegates appear unpromising for now.

Rubio said last week that he wants a conservative nominee, and the only conservative still in the race is Ted Cruz. He stopped short of an endorsement because that would have freed his delegates. But nearly all the Rubio backers at the Colorado Republican convention on April 8 helped Cruz win all of the state's 34 delegates.

And most of Rubio's delegates, once released by Rubio himself, are unlikely to migrate to Trump on their own. It would probably take a strong effort by Rubio to persuade a chunk of them to vote for Trump.

Kasich is another story. His strategy is to remain a candidate through early ballots on the hope that Trump and Cruz fail to win a majority and the convention turns to him as an electable alternative.

Trump would have to coax Kasich into dropping out. He has 143 delegates and may win a few more. He may be unwilling to let them go. But Trump can be persistent. "I aim very high and then I just keep pushing and pushing and pushing to get what I'm after," he wrote.

Newt Gingrich, a friend of Trump who talks to him frequently, says Trump will have to negotiate "even if he's at 1,237" when the convention begins in Cleveland on July 18. He will have to deal with unhappy Republican and conservative leaders to create party unity. "There's no way he can avoid negotiating," Gingrich says.

This may be Trump's most difficult task, assuming he's the nominee. The Republican party is divided, and many of Trump's foes say they won't vote for him under any circumstances. He may also face the threat of a third-party conservative candidacy that could draw millions of votes from him.

For unity's sake, he may have to make serious concessions to the point of violating his own rules. "The worst thing you can possibly do in a deal is seem desperate to make it," he wrote in The Art of the Deal. "That makes the other guy smell blood, and then you're dead. The best thing you can do is deal from strength, and leverage is the biggest strength you can have. Leverage is having something the other guy wants. Or better yet, needs. Or best of all, simply can't do without."

But if he's a nominee threatened with mass defections, he wouldn't be dealing from strength. His critics would have the leverage. They would have something he needs, the ability to provide unity. And that's something he couldn't do without.

There's one more situation where Trump would be pressed to negotiate: if he loses the nomination and claims he was cheated. Having Trump march out of the convention in a huff would be a problem for the nominee who beat him.

What might assuage Trump, softening the blow to his ego? The nominee could hint that he would make a fine Treasury secretary. But there's a better option. Trump could be given the job of building the wall along the border with Mexico. A crazy idea, for sure, but not a bad one.

Fred Barnes is an executive editor at The Weekly Standard.