Donald Trump and Elon Musk are in a public fight. It started over tax policy. Trump says he cut Musk out of EV decisions. Musk retaliated with an Epstein accusation. Trump threatened to end Musk's government subsidies. US regulators may target Musk's companies like Tesla and SpaceX. The FCC, FDA, EPA, NHTSA, FAA, and SEC oversee Musk's various ventures.