Choosing billionaire Elon Musk to be what President-elect Donald Trump calls “our cost cutter” for the U.S. government, is not the first time an American president has empowered a business tycoon to look for ways to dramatically cut federal regulations.

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 spent days bounding in and out of meetings, sitting in on phone calls, weighing resumes and traveling to Washington as Trump’s unofficial co-president.