The decision-making guy at the fair, Gary Slater (whom I know), says no such request has been made yet, and with two weeks until the fair opens, it can’t happen anyway.
The problem is space. The fairgrounds is in town, not level, and surrounded by residential areas. Largest open space is the race track/main stage, which already has stuff set up.
He could wave enough cash around and might get a private party nearby with space, but it’s a big ‘copter and the room isn’t there on the fairgrounds that isn’t long ago accounted for.
Most fairs have their booths, and rides scheduled years in advance. I think Trump can still pull this off somehow. Maybe not at the fairgrounds, but............
That's the Art of the Deal. Otherwise, it's like killing Santa Clause if he just says "no" to the generous gift.