In a recent lecture titled “The Fiscal Future,” Professor N. Gregory Mankiw of Harvard University laid out the following future scenarios as our federal debt explodes. And it does not account for the so-called ‘Big Beautiful Bill’ that President Trump just signed into law, which will steepen the ascent of government debt.”An excessive federal debt could overwhelm financial markets both at home and abroad. President Clinton addressed a rising debt-to-G.D.P. But the debt stabilization contributed to economic prosperity, and by the end of the decade, the federal debt had dropped to 55 percent of G.D.P. If President Trump does not want to think about the Clinton policies of 1993, he can look back further in time to President Eisenhower.