After four months on the job, billionaire Elon Musk has finished his role in the Trump administration as a top adviser to the president. Musk’s effort to improve government efficiency was marked by controversy and fell far short of his goal to reduce spending. He dramatically cut his target from $2 trillion to $1 trillion to $150 billion. Early on, he held a chainsaw in the air to illustrate the laying off of thousands of government employees and the gutting of agencies like USAID. Musk now shifts his attention back to running his businesses, including Tesla and SpaceX. Before leaving the White House this past week, he told CBS he was “disappointed” in President Trump’s tax-and-spend bill, which he said will increase the size of the federal deficit.