Joe Biden spent an astonishing 47 years in public life without winning a single presidential primary, but now he owes his near-certain capture of the Democratic nomination to three statements, each about one minute long, that other key Democrats made in the course of just 16 days.

On Feb. 11, Biden’s campaign seemed as dead in the water as his efforts in the 1988 and 2008 presidential cycles had been. Pete Buttigieg and Bernie Sanders that day had virtually tied in the second consecutive state nominating contest (New Hampshire, after Iowa eight days earlier), Amy Klobuchar was outpacing Biden as the top “moderate” vote-getter, and Michael Bloomberg rose in national polls by spending half a billion dollars.