Is our national debt finally too much? (update)

Planet Money revisits the question of when the U.S. national debt becomes too large, a debate that exploded in 2010 when two economists tried to pin down a specific threshold. Their work sparked a decade-long academic dispute that exposed deep disagreements in macroeconomics. Now with $40 trillion in debt, interest rates elevated, and a political shift toward fiscal hawkishness, the team asks if we've crossed a red line. The answer remains as elusive as ever, illustrating the uncertainty at the heart of economic forecasting.