If Trump wants it, the nomination if his. The real contest is for the number two slot. The one who figures this out, wins. Bigly.
I suspect
@Right_in_Virginia is correct, the nomination is Trump's if he wants it.
But the idea that the running-mate position will be some kind of big prize is risible. Everyone knows Trump destroyed and alienated all the people that he himself selected; no one in their right mind will want the number two slot, or any other slot in a second Trump administration. No one wants to be the next Mike Pence, or Rex Tillerson, or Jim Jeffords, or Reince Priebus, or Sean Spicer, or John Kelly, or Anthony Scaramucci, or Jim Mattis, or Bob Barr. Everyone Trump touches turns to lead.
I'm a University of Tennessee football fan. We Vol fans maintain this delusion that the head coaching job there is a plum position, one of the best in the country, but in reality it's not. The program has declined so far and the fans are so fickle and unreasonable that the job is not desirable, and can only attract dark horse and second-tier candidates. Working for Trump is basically a football coaching position at the University of Tennessee; it's a bad career move and the kind of people we would want there are very unlikely to accept the job.
DeSantis might have to wait out a second Trump administration, but he doesn't need Trump for anything. Trump's first administration demonstrates that accepting a VP slot with him would have far more potential downside than up side. And before we accept the idea that DeSantis needs to learn anything from Trump, how about we identify a single prominent, successful person who considers Trump a mentor.
What the country needs is Trump's policies. His people management record in the White House was abysmal.
Vol football fans can list all the reasons that the last few coaches were all bad hires. And I'm sure we can quickly make up a long list of reasons why all those former first Trump administration officials were all terrible people.
Remember who selected them.