Bill Ackman said on Friday that he'd serve under Elon Musk in the Trump administration. Musk has promised "temporary hardship" for Americans under a budget-cutting plan. Billionaires are lining up to serve in President-elect Donald Trump ‘s incoming administration, especially those eager to cut federal assistance programs.

The billionaire is enthusiastic about the potential to bring his slash-and-burn business philosophy, honed at Twitter and Tesla, to dramatically cut the federal government under Trump. Critics see potential conflicts of interest.