What if Trump let the GOP pick his VP?

Even after his big win in the New York primary on Tuesday, Donald Trump still isn't likely to come into the GOP convention in Cleveland this July with the 1,237 delegates needed to clinch the nomination on the first ballot.

The key for him could be all about the running mate. He can choose one pre-convention who will help him win new delegate support. A smart move there could finally give Trump just enough support from inside the Republican Party to not only get the nomination, but grab it on the first ballot.

It's really important to grasp just how different the running mate stakes are for both Trump and Hillary Clinton compared to every presidential election for the last 56 years. This year, both front-runners have to choose their running mates with their eyes almost entirely on securing their nominations and not the general election.

The last time that happened was in 1960, when the generally liberal Northeasterner John F. Kennedy needed to join forces with Lyndon Johnson to consolidate wavering Southern Democratic Party support for his candidacy. This would be an issue JFK had to deal with time and again. Trying to rein in potentially mutinous Southern Democrats was even the reason President Kennedy was in Dallas with LBJ in tow the day he was assassinated, ironically by a Communist sympathizer. The Kennedy campaign really didn't think much about whether LBJ was going to be too much of an asset in the general election. Consolidating party unity and assuring JFK's nomination were the only real concerns.

The 1960 GOP nominee Richard Nixon had the same problem: He was still seen as an upstart Westerner even though he had been vice president for eight years. He was thus forced to choose the Northeastern "establishment" figure Senator Henry Cabot Lodge from Massachusetts, which was also Kennedy's home turf and a state Nixon and the GOP knew they had no chance of winning in November. But securing the nomination was also the only real concern.

So what options does Trump have to make up with today's so-called GOP "establishment?" It's something his new team of more professional campaign managers needs to consider because there will be 150-200 delegates who will be coming to Cleveland undeclared for any candidate. A good running-mate strategy could easily sway those free agents and give him the nomination on the first try.

Trump has to choose between two strategies. First, he could decide to name his running mate well before the convention and choose someone many of his most ardent opponents inside the Republican Party will like. Based on the bad blood between Trump and Senator Ted Cruz, and the fact that most elected Republicans don't like Cruz either, I don't see Cruz being a viable choice. Governor John Kasich is a bit more of a plausible choice, and some GOP insiders seem to think Kasich has been angling for the VP slot all along. And he offers the hint of general election help with his popularity in the crucial state of Ohio. But Kasich's many recent comments disparaging Trump and even saying he's not fit to be president are going to be hard to ignore. Still, it would be hard for Trump to do better in his attempts to appear more conciliatory than he could by finding some way to join forces with Kasich.

On CNBC Wednesday morning, Steve Forbes put forth the possibility that Trump will pick a wildcard running mate like former Secretary of State Colin Powell. But Powell has almost completely left the Republican Party and it's hard to believe the very moderate in philosophy and demeanor Powell will come back to join the bombastic and divisive Trump.

Actually, there is one possibly better option: Trump could do what a few presumptive nominees have done in the past and let the convention delegates know that he will allow them to choose his running mate for him. As long as Trump makes that announcement well enough in advance of the convention, it would send the message to the party fathers at large that he's not going to make this election all about him. It would also give the traditional party leaders a chance to participate in the running mate sweepstakes and make plenty of their own deals and partnerships.

Commentary by Jake Novak, supervising producer of "Power Lunch." Follow him on Twitter @jakejakeny.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.