Can Elon Musk save $2 trillion for Donald Trump?

Elon Musk, Tesla CEO and SpaceX founder, has now been appointed to co-head a new Department of Government Efficiency by the incoming US president Donald Trump, giving him an opportunity to try to put his plans into action. Elon Musk, wants to take at least $2 trillion off the top of the annual federal budget. But is that proposal realistic?