When you own a legal printing press running it just to pay your bills is how you default. One more time in large cheerful letters:“’This is the United States government. First of all, you never have to default because you print the money. I hate to tell you. So there’s never a default. But the point is it was reported in the New York Times incorrectly,’ he said, referring to a critical Times article that ran on Friday.”
Devaluation = Default
So what the great business man is proposing is to borrow massive amounts of money, spend it all on "infrastructure" then when the Keynesian economics fail to work we turn the world's(including our) reserve currency into toilet paper.