The ridiculous number of candidates on the Democratic stage last night created a fundamentally misleading aural and visual impression. Watching without access to polling data, you might have imagined that this was some sort of wild careening mess of a primary race, when really it’s remarkably consolidated.

There is a Joe Biden constituency that seems stable at around 30 percent of the primary electorate. There is an Elizabeth Warren constituency that has expanded swiftly enough, especially in early states, to make her arguably the front-runner. There is a Bernie Sanders constituency that is about two-thirds the size of Warren’s and Biden’s peak and seemingly stuck there. And then, way down at around 5 percent and under, there is everybody else.

So a big question in this debate and in the ones before Iowa arrives and the also-rans begin to be formally run out is whether Democratic voters can be persuaded to reconsider this consolidation. And last night there were only really two candidates who presented themselves as plausible vehicles for that reconsideration: Pete Buttigieg and Amy Klobuchar.

As for the others — well, Andrew Yang and Tulsi Gabbard are too niche, Beto O’Rourke is too limp, Julián Castro is too forgettable and Tom Steyer is too absurd. Meanwhile, Kamala Harris and Cory Booker should be contenders, but Booker manages to be appealing at every debate without quite finding a rationale for his candidacy, while Harris has been on a weird self-destruct mission ever since her brief ascent — with her strange fight with Warren last night over whether Twitter should ban Donald Trump a particularly peculiar self-charted nose-dive.