[dropcap]P[/dropcap]resident Donald Trump’s rally in Missouri was a set-piece of distortion about taxes and the economy” that “compounded his growing legacy of false tales on Twitter . . .”

Those weren’t the opening lines from some loser liberal commentator. They were from the Associated Press.

The editors at AP at some point realized that their job wasn’t just to report what newsmakers say but also whether what they say is false.

In the speech in question, AP re...