"This large amount of debt is a serious problem for the country. Even though interest rates are near zero, the interest expense on the debt will be about $400 billion this year. "

Why would the monopoly issuer of the US dollar ever need to "borrow" its own currency back, and how would it do so if it didn't first create those dollars to make them available to be borrowed? One cannot borrow or collect what doesn't yet exist. If I'm wrong please point me toward this source of dollars being loaned so I can get in on this action as well.

The primary tool used by most "deficit hawks" is deflection away from the fact that every dollar the federal government spends above its tax collections, including the interest paid on Treasuries, is a net gain of assets for someone, not simply a number on a spreadsheet standing alone. The debt (the aggregate of deficits over time) is nothing more than an accurate accounting of our nation's money supply. It is the profit made from our commerce with our government and the only store of monetary value available that can be net saved or used to retire private sector bank debt.