Billionaire Elon Musk’s deputies have gained access to a sensitive Treasury Department system responsible for trillions of dollars in U.S. government payments after the administration ousted a top career official at the department, according to three people who spoke on the condition of anonymity to describe government deliberations.Subscribe for unlimited access to The PostYou can cancel anytime.SubscribeOn Friday, Treasury Secretary Scott Bessent approved access to the Treasury’s payments syst...