WaPo:

Justice Sonia Sotomayor will not participate in one of the two cases the Supreme Court will hear in April to decide whether the Constitution forbids states from dictating how members of the electoral college cast their votes for president.

The clerk of the court informed lawyers in the case Tuesday that Sotomayor realized she is friends with one of the parties in one of the cases, from Colorado. Sotomayor will still participate in the other case, from the state of Washington.

“The justice believes that her impartiality might reasonably be questioned due to her friendship with respondent Polly Baca,” Supreme Court Clerk Scott S. Harris wrote. “The initial conflict check conducted in Justice Sotomayor’s Chambers did not identify this potential conflict.”