“Elon Musk does not have the power to fire people,” Mr. Scott said on CNN’s “State of the Union.” “The president of the United States is Donald Trump, and the agency heads are the ones who manage each of their departments, so they’ve got the — they’ve got the decision, that’s what Elon Musk has told me time and time again.”

The dynamic of cutting government while also cutting out those who answer to voters has alarmed even some fiscal conservatives who have long pushed for Congress to reduce spending.