Tesla remains Musk’s best-known business, but its fortunes are less directly tied to the government than SpaceX, his rocket-building company.

The feud between Elon Musk and President Donald Trump heated up again Tuesday after the billionaire slammed Republicans over the president's spending bill.

U.S. Senate Republicans passed President Donald Trump's massive tax-and-spending bill on Tuesday by the narrowest of margins, advancing a package that would slash taxes, reduce social safety net programs and boost military and immigration enforcement spending while adding $3.3 trillion to the national debt.