Elon Musk’s influence over the federal government is extraordinary, and extraordinarily lucrative.

Mr. Musk’s rocket company, SpaceX, effectively dictates NASA’s rocket launch schedule. The Defense Department relies on him to get most of its satellites to orbit. His companies were promised $3 billion across nearly 100 different contracts last year with 17 federal agencies.

His entanglements with federal regulators are also numerous and adversarial. His companies have been targeted in at least 20 recent investigations or reviews, including over the safety of his Tesla cars and the environmental damage caused by his rockets.

Given Mr. Musk’s immense business footprint, he will be a major player no matter who wins the election.

But he has thrown his fortune and power behind former President Donald J. Trump and, in return, Mr. Trump has vowed to make Mr. Musk head of a new “government efficiency commission” with the power to recommend wide-ranging cuts at federal agencies and changes to federal rules.