Unlock the US Election Countdown newsletter for free
The stories that matter on money and politics in the race for the White House
Not far from Times Square in Midtown Manhattan, a giant screen displays a fast-changing string of 14 digits. Soon the number will flip above $35tn, as the quantity of US government debt spirals to a new record. There is space on the US debt clock for another couple of digits, allowing the display to reach into quadrillions. The only snag: the trajectory of…