Chief Justice John Roberts on Thursday rejected Senate Democrats’ request to meet to discuss the Supreme Court ethics firestorm surrounding Justice Samuel Alito.

“I must respectfully decline your request for a meeting,” Roberts wrote to Senate Judiciary Committee Chairman Dick Durbin (D-Ill.) and Sen. Sheldon Whitehouse (D-R.I.), who chairs a subcommittee on the federal courts.

“Separation of powers concerns and the importance of preserving judicial independence counsel against such appearances,” said the chief justice. “Moreover, the format proposed ― a meeting with leaders of only one party who have expressed an interest in matters currently pending before the Court ― simply underscores that participating in such a meeting with be inadvisable.”

Here’s a copy of Roberts’ letter:

Roberts’ letter comes days after top Democrats on the Senate Judiciary Committee requested a meeting “as soon as possible” to discuss the need for Alito to recuse himself from cases related to the 2020 presidential election.

Recent news reports revealed that Alito flew flags at two separate residences — the “Appeal to Heaven” flag and an upside-down U.S. flag — known to be symbols of support for the insurrectionists who attacked the U.S. Capitol on the Jan. 6, 2021. Since the flag incidents came to light, Democrats in both chambers have fumed about Alito, arguing he violated the court’s code of conduct.

In his Thursday letter, Roberts also noted that Alito has already sent senators a letter laying out why he won’t recuse himself. Alito blamed his wife for raising the flags at his residences, and said that because she has the legal right to fly whatever flags she wants on their property, “there were no additional steps that I could have taken to have the flag taken down more promptly.”

With the Supreme Court chief justice refusing to meet with them and Alito refusing to recuse himself, the only real recourse Democrats have left is to subpoena Alito to appear before the Senate Judiciary Committee and explain himself. Durbin has this authority, but has not used it thus far.

Durbin couldn’t do this unilaterally, though. He’d either need the top Republican on the committee to sign off, which won’t happen, or a majority vote in the committee. It’s not clear that all 10 Democrats on the committee would vote for such an escalation, either.

A judiciary committee spokesperson last week declined to say whether Durbin is prepared to try to subpoena Alito. Instead, Durbin remains focused on continued committee investigations into justices’ ethical lapses and on trying to pass a Supreme Court ethics bill, the spokesperson said.

That bill, the Supreme Court Ethics, Recusal and Transparency Act, would require justices to adopt a binding code of conduct and improve transparency when a justice has ties to a party before the court.

It has next to no chance of passing either chamber of Congress.