Trump has asked aides and advisers if they believe Musk’s recent behavior could be related to his alleged drug use.

Elon Musk’s final hours working for President Donald Trump were spent in part by deflecting questions about his drug use

Separately, White House aides, after working to persuade the president to temper his public criticism of Musk to avoid escalation, scheduled a call Friday with the billionaire CEO of Tesla to broker a peace.

The broken alliance between the President and world's richest man could threaten Musk's lucrative pending -- and future -- federal subsidies.

The risk U.S. transportation, environmental, communications and other regulators will take aim at Elon Musk's many businesses became a real threat after the billionaire's deep political ties with President Donald Trump disintegrated on Thursday.