The evening was defined by peevish exchanges, raised voices, feeble attempts at humor, complaints about fairness in being allowed to speak, and extended passages of cross-talk in which moderators utterly lost control of the debate and it was impossible even to understand what was being said. The noise was hardly conducive to a sustained or intelligible argument about whether Sanders is the strongest nominee or the one most representative of the views and temper of the party.

The evening offered limited opportunities—were these possibly enough?—for six Democrats not named Sanders to revive their candidacies with last-stand moments to emerge as the main alternative to the self-described democratic socialist for the balance of the nomination contest. This last-stand is especially urgent for former Vice President Joe Biden, who repeated his vows to win the South Carolina primary on the strength of his connection with African-American voters.

The second strategic challenge is to convey what most Democrats regard as the gravity of the case against President Donald Trump. Much of the debate seemed divorced from the present moment, as the president in the wake of his impeachment acquittal has embarked on a so-called Revenge Tour.