WASHINGTON – Senator Patrick Leahy, D-Vt., said he may propose legislation that would allow a retired U.S. Supreme Court justice to sit in a case when a current justice has recused—in what would be a major shift in how the Court operates.

The idea has been raised as Justice John Paul Stevens prepares to join the ranks of retired justices. Mr. Leahy, who chairs the Senate Judiciary Committee, said he decided to draft a bill after a recent meeting with Justice Stevens.