Some people have called for a balanced budget amendment to our Constitution as a means of reining in a big-spending Congress. That's a misguided vision, for the simple reason that in any real economic sense, as opposed to an accounting sense, the federal budget is always balanced. The value of what we produced in 2017 -- our gross domestic product -- totaled about $19 trillion. If the Congress spent $4 trillion of the $19 trillion that we produced, unless you believe in Santa Claus, you know that Congress must force us to spend $4 trillion less privately. Taxing us is...