Ohio Gov. John Kasich (R) pointed to the debt clocks displayed at the Republican National Convention, calling them the "sword of Damocles" hanging over our heads. In case that reference left you scratching your head, here's classics scholar Daniel Mendelsohn explaining on NPR what the phrase means and how it's often misused. 

DANIEL MENDELSOHN: The story goes that Dionysius, the tyrant of Syracuse had a courtier named Damocles who was more or less a professional flatterer who lay around these opulent feasts saying nice things to Dionysius.

And once, he made a comment to the effect of, oh, how great it would be to be the king. And Dionysius said, oh, really? Well, if you want to know what that's like, you can come sit in my throne, which Damocles did and Dionysius made sure that he was well supplied with opulent food and great service and cute waiters and beautiful perfumes and scented candles going.

And Damocles was thinking to himself, how very wonderful then, it must be and then noticed that Dionysius had also hung above the throne a gleaming sword, which was suspended by a single horsehair. And he then begged Dionysius to be allowed to leave the throne and to go back to his subservient position as a courtier and obviously got the point, which is that anybody who gets to enjoy immense wealth, luxury and power also is living under a threat.