The U.S. national debt is rapidly approaching the $40 trillion threshold, and about one-fourth of that debt has been incurred while President Donald Trump has been in office.Spending by the federal government has accelerated dramatically as the U.S. population has aged, with increased enrollment in Social Security and Medicare pushing spending on those entitlement programs higher and contributing to the growth in federal budget deficits.The recent rise in interest rates — coupled with the larger national debt — has exacerbated that trend, with interest expenses from servicing the national debt...