Musk has emerged as a prominent member of Trump's inner circle. Tesla has lobbied for electric vehicle subsidies and other benefits over the years.

Musk has been so aggressive in pushing his views about Trump’s second term that he’s stepping on the toes of Trump’s transition team and may be overstaying his welcome at Mar-a-Lago, Trump’s home in Palm Beach, Florida, according to two people familiar with the transition who have spent time at the resort over the past week.

In picking billionaire Elon Musk to be “our cost cutter” for the U.S. government, President-elect Donald Trump won't be the first American president to empower a business tycoon to look for ways to dramatically cut federal regulations.