fool's errand

Trying to predict Donald Trump's economic policy decisions from one moment to the next is a fool's errand.

“It’s like a game of Whack-a-Mole, and things keep popping up. … The definition of enough depth, I think is a fool’s errand. I don’t know what enough depth means. I think more is always better with pitching depth.”

But hoping for nuance in this franchise is a fool’s errand.

But it would be churlish to say either way, comparing eras is a fool's errand.

“To try and extract more water from a system that doesn’t have it is just a fool’s errand,” he said.