You don’t need 20% interest rates to keep inflation under control. 7% will do quite nicely, given the indebtedness of the American consumer. Also, just because the defict doubles doesn’t mean interest payments double. It takes a while for the debt to build up. If the government ran $2 trillion deficits for 3 years, that would add $6 trillion in new debt, which would then cost an additinal $420 billion/year in interest payments at 7%, or perhaps 3% of GDP. This is quite manageable. What happens if these huge debts continue beyond 3 years is another story. At that point, I might indeed start getting worried.

There is no such thing as “printing” money in today’s economy. Do you mean the Fed will keep interest rates low in the presence of high inflation caused by a huge budget deficit? Possibly, though there is absolutely no past precedent for such a thing.

You make it sound like raising interest rates to accomodate a huge budget deficit will encounter massive resistance. But actually it is the path of least resistance. Congress gets to spend lots of money, which most voters like, while the people who get hurt are the net debtors, and those who have lent to these debtors. The debtors are poor, while the lenders are rich, but Congress will likely be in a mood to make scapegoats out of the rich banks by this time next year. Expect a new law making bankruptcy much easier. That’s the real American way to clean up a debt mess.