The exterior of the Supreme Court building in Washington, DC, November 30, 2018.
CNN  — 

Democrats on the Senate Judiciary Committee said Monday that they planned to schedule a vote to authorize a round of subpoenas related to their investigation into ethics reform at the Supreme Court after an array of stories over the last several months have suggested that some of the justices, Clarence Thomas in particular, have skirted ethics rules.

“The Supreme Court is in an ethical crisis of its own making,” Chair Dick Durbin, an Illinois Democrat, said in a statement and announced that the subpoenas would target Harlan Crow, Leonard Leo and Robin Arkley II, who have all been linked to Thomas and others in recent news stories.

Durbin noted that Crow and Arkley, wealthy conservative donors, and Leo, a longtime conservative activist, had declined to fully engage with the committee on a voluntary basis during its inquiry. “Due to Crow, Leo and Arkley’s intransigence, the Committee is now forced to seek compulsory process to obtain the information they hold,” Durbin said.

In a statement, the office of Harlan Crow called the committee’s effort a “stunt aimed at undermining a sitting Supreme Court Justice for ideological and political purposes.” “Mr. Crow, a private citizen, won’t be bullied by threats from politicians. However, as previously conveyed to the Committee, we remain committed to respectful cooperation and a fair resolution,” it added.

A lawyer for Crow had been negotiating for Crow to supply the committee with some information related to the travel and luxury vacations he gifted to Thomas over the past five years but the offer was ultimately rejected by Democrats who wanted more information spanning their long friendship.

In a statement provided to CNN, Leo said he “will not bow to the vile and disgusting liberal McCarthyism, that seeks to destroy the Supreme Court simply because it follows the constitution rather than their political agenda.” In a letter sent to the committee earlier this month, Leo’s attorneys described the inquiry as “political retaliation.”

CNN has reached out to Arkley and the Supreme Court for comment.

The Senate Judiciary Committee is likely to vote on the subpoenas on November 9, according to a Democratic aide.

The news marks an escalation of the Senate’s investigation and comes as Democrats are pushing regulations that would require the justices to adopt a code of conduct directed specifically at the high court. It is sure to trigger new separation of powers concerns between the branches of government.

Last July, Justice Samuel Alito argued in an interview published by the Wall Street Journal that Congress should stay out of the Supreme Court’s business and stop trying to impose ethics rules on justices and clerks. “Congress did not create the Supreme Court,” Alito said. “I know this is a controversial view, but I’m willing to say it. No provision in the Constitution gives them the authority to regulate the Supreme Court—period,” he said.

The latest allegation against Thomas occurred last week after The New York Times reported that he failed to repay a “significant” portion of a $267,230 loan from a friend that allowed him to by a luxury motorcoach in 1999, according to a memo issued by Democrats on the Senate Finance Committee. Hours after the report appeared, a lawyer for Thomas disputed the findings arguing that the loan had never been forgiven. “The Thomases made all payments,” the lawyer, Elliot S. Berke, said in a statement to CNN.

But Berke would not address any follow up questions concerning whether the payment was for both principal and interest. In a 24-part post on X on Monday, Thomas’ longtime friend Mark Paoletta blamed critics of Thomas, writing that the left “wants to destroy the Court” because it is no longer liberal. Paoletta also said that neither the friend, Anthony Welters, nor Thomas has maintained all the records concerning the loan because it occurred nearly 25 years ago.

In the last several months, four justices – Chief Justice John Roberts and Justices Brett Kavanaugh, Elena Kagan and Amy Coney Barrett – have expressed various forms of support for some kind of ethics reform at the high court, although no announcement has been made.

ProPublica reported during the high court’s last term that Crow – a GOP megadonor – had