ABC’s Matter-of-Fact Moderators Built Factual Guardrails Around Trump

Fifteen minutes into Tuesday’s debate, former President Donald J. Trump was delivering a circuitous answer about his stance on abortion rights when he made a statement with no basis in reality: that a governor had condoned executing babies after birth.

Linsey Davis, one of the evening’s moderators from ABC News, did not let that one slide. “There is no state in this country where it is legal to kill a baby after it’s born,” Ms. Davis said, matter-of-factly.

A little later, it happened again. When Mr. Trump made an outlandish claim about migrants in an Ohio town eating dogs and cats, the other moderator, David Muir, pointed out that ABC had called the city manager and learned there were no credible reports of pets being harmed.

“The people on television say, ‘My dog was taken and used for food,’” Mr. Trump said.

“I’m not taking this from television,” Mr. Muir responded. “I’m taking it from the city manager.”

In the context of 105 minutes of fierce debate in Philadelphia, these exchanges were fleeting. But they signaled a shift — for an evening, at least — in the balance of power between Mr. Trump and the many journalists who have struggled, or stopped trying, to construct factual guardrails around the bombardment of baseless claims that he regularly unleashes on live TV.

Using calm and authoritative tones, Mr. Muir and Ms. Davis offered a model for real-time fact-checking that has been absent from many recent presidential debates. Mr. Trump’s apocalyptic portrait of an America besieged by migrant crime was met by Mr. Muir’s polite reply: “As you know, the F.B.I. says overall violent crime is coming down in this country.”