The debate follows another turbulent day in Iowa. After initially demanding a recanvass of results in the entire state, the head of the Democratic National Committee, Tom Perez, backtracked and said that only precincts with reported problems needed to be re-examined. Here’s a county-by-county map of results.

My colleague Maggie Astor reports: “It is very easy, at this point, to imagine a situation in which we know who won New Hampshire — which holds its primary on Tuesday — before we know who won Iowa.”

Closer look: A Times analysis found that the results released by the Iowa Democratic Party were riddled with errors.

Another angle: We asked the candidates about foreign policy and national security. Our survey found a party only partially committed to the Obama era, and unified by very few issues: most prominently the containment of Russia.