Senate Judiciary Committee Chairman Dick Durbin (D-Ill.) on Tuesday said GOP megadonor Harlan Crow “did not provide a credible justification” for not providing the panel with information related to the gifts he has given to Justice Clarence Thomas over the years.

An attorney for Crow said in a letter dated Monday and obtained by The Hill that they “do not believe the Committee has the authority to investigate Mr. Crow’s personal friendship with Justice Clarence Thomas.”

Michael Bopp, a lawyer at Gibson Dunn, wrote to Durbin that “Congress does not have the constitutional power to impose ethics rules and standards on the Supreme Court. Doing so would exceed Congress’s Article I authority and violate basic separation of powers principles.”

“Separately, the Committee has not identified a valid legislative purpose for its investigation and is not authorized to conduct an ethics investigation of a Supreme Court Justice. The Committee’s stated purpose of crafting new ethics guidelines for the Supreme Court is inconsistent with its actions and the circumstances in which this investigation was launched, all of which suggest that the Committee is targeting Justice Thomas for special and unwarranted opprobrium,” Bopp continued.

Durbin said the panel also did not receive any response from the holding companies that own the private jet, yacht and Camp Topridge — Crow’s private lakeside resort — to written questions. 

“Harlan Crow believes the secrecy of his lavish gifts to Justice Thomas is more important than the reputation of the highest court of law in this land. He is wrong,” Durbin said.  

“The Committee will respond more fully to this letter in short order, and will continue to seek a substantive response to our information requests in order to craft and advance the targeted ethics legislation needed to help restore trust in the Supreme Court,” he continued. 

Durbin added that if Chief Justice John Roberts does not act to institute a new ethics code for justices, then Congress will have no choice but to act. 

Roberts last month declined a request by Durbin to testify before the Judiciary Committee to discuss Supreme Court ethics at a hearing centered on that subject. He cited the “exceedingly rare” nature of a chief justice providing testimony to a Senate panel. 

According to recent reports, Crow, a friend of the longtime justice and his wife, , has footed the bill for luxury trips taken by the couple and purchased a house owned by Thomas’s mother in which he had an interest. Neither were disclosed. 

In addition, Crow reportedly paid for the tuition of Thomas’s grandnephew. That also was not disclosed. 

Updated at 2:05 p.m.