Last Friday, as jurors in the Lindsay Clancy murder trial filed into a Massachusetts courtroom one last time, followers knew the outcome would come down to a lone holdout. With the jury deadlocked 11-1 and the judge’s declaration of a mistrial, Americans reacted with fierce division. The holdout was a hero or a pariah.

Ms. Clancy, 36, admitted to strangling her three children in 2023 while experiencing severe mental illness. Her supporters, and nearly all of the jury, concluded she was too sick to understand her conduct was criminal on the night she killed Cora, 5, Dawson, 3, and Callan, 8 months, and should be found not guilty and confined in a psychiatric hospital indefinitely. Another faction believed she should be held criminally responsible and spend the rest of her life in prison.

To them, the anonymous juror who cast the only vote for her conviction acted with inspiring moral courage. But to many who hoped for acquittal, the holdout embodied society’s lack of compassion. Several jurors said the holdout did not follow the judge’s instructions or the law, and stood by his vote even after acknowledging reasonable doubt. Ms. Clancy’s lawyer, Kevin Reddington, filed a motion for the mistrial to be thrown out and for her to be acquitted. The conflict has been explicitly political and gendered, with attacks on both sides turning personal.