Default is a four letter word

Here's a scary statistic:

[ NYTimes ] With the national debt now topping $12 trillion, the White House estimates that the government’s tab for servicing the debt will exceed $700 billion a year in 2019, up from $202 billion this year, even if annual budget deficits shrink drastically.

Keeping in mind that these things always turn out worse than expected, and that it assumes "budget deficits shrink drastically", this is shocking. 700 Bil was the size of the entire federal government budget the year I was born. In 40 years, we've gone from that, to that merely being our mortgage payment.