Chief Justice John G. Roberts Jr. on Thursday declined requests to have Justice Samuel A. Alito Jr. recuse himself from cases related to the Jan. 6 Capitol attack after provocative flags flew on the justice’s properties.

The justices make those calls on their own, Chief Justice Roberts wrote in a letter to Democratic senators.

“Members of the Supreme Court recently reaffirmed the practice we have followed for 235 years pursuant to which individual justices decide recusal issues,” he wrote.

The chief justice also rejected a request to meet with Democratic senators to discuss ethics at the Supreme Court, writing that doing so would raise concerns about separation of powers and judicial independence.

Sitting down with leaders of one political party “who have expressed an interest in matters currently pending before the court,” he wrote, would only underscore that “such a meeting would be inadvisable.”