> What does it have to do with Trump then? Why was he involved?

One of the broken parts of the American system is permitting. Trump can sidestep that by letting this be built on federal land. That, in turn, unlocks investment.

Beyond that, DoD and DoE are massive buyers of compute. Seeding the venture with purchase agreements from them de-risks the project further.

Finally, by Trump putting his name to it he assigns it his bully pulpit's prestige. (Though that doesn't appear to have carried over to Musk, who's already taking pot shots at it.)