Before the Republican presidential debate at the Reagan Library Sept. 16, CNN promised to stage what it called “actual debating.”

“Is one of the goals for you … to spur more actual debating?” CNN’s Brian Stelter asked debate moderator Jake Tapper a few days before the event. Stelter pointed to a moment in the August Fox News debate in which two candidates, Chris Christie and Rand Paul, had an extended and heated — and illuminating — exchange with each other.*