He's just an idiot. The US already has a Ford class aircraft carrier that has conducted tens of thousands of sorties using EMALS since October 2023 in the USS Gerald R Ford. The US successfully launched an F-35C from a ground based EMALS catapult 12 years ago. The USS Gerald R Ford doesn't operate F-35Cs as part of it's air wing, because of a procurement decision to equip older Nimitz class carriers like the Carl Vinson and George Washington with the support equipment for F-35Cs first. The second Ford class carrier, the USS John F Kennedy, has already tested it's EMALS in trials. The US is not going back to steam, Trump just doesn't like magnets for whatever reason.