Democrats on the Senate Judiciary Committee sent a letter Monday to the conservative billionaire donor who has acknowledged paying for luxury vacations for Supreme Court Justice Clarence Thomas and private school tuition for Thomas’ nephew. 

In the letter, Senate Democrats requested that Harlan Crow provide a list of all gifts, payments and other items exceeding $415 in value that he or any entities he controls have given Thomas or his family members.

The senators also want Crow to disclose all of Thomas’ transportation and lodging that he paid for and a list of any private gatherings he was involved with that Thomas attended, along with a guest list. The letter also asks for Crow to disclose all real estate transactions he’s made with Thomas. 

“We’re seeking information on whether individuals with interests before the Supreme Court were able to gain access to Justices through gifts, lodging, and travel from Harlan Crow and his companies,” Sen. Dick Durbin, D-Ill., the committee’s chairman, tweeted Tuesday morning. 

The letter was signed by all 11 Democratic members of the panel. 

They also sent separate letters to the entities that own Crow’s private upstate New York resort, yacht and private plane, asking them to provide lists of other guests or passengers who might have had access to Thomas.

The senators wrote in the letter that the information is needed as part of the committee’s efforts to introduce legislation that would strengthen ethics rules for Supreme Court justices.

Sen. Ron Wyden, D-Ore., chairman of the Senate Finance Committee, also said last week he’d been pushing to have Crow testify about “his lavish gifts to Clarence Thomas.” The Hill reported Tuesday that Crow, through his attorney, declined to turn over to the Finance Committee a list of gifts he gave to Thomas, citing "serious concerns about the scope of and authority for this inquiry."

Last month, ProPublica reported that Crow paid for private flights and luxury vacations for more than 20 years for Thomas, who did not disclose the travel. Thomas also reportedly did not disclose that he sold real estate to Crow, an apparent violation of reporting requirements.

And last week, ProPublica reported that Crow paid thousands of dollars in private school tuition for Thomas’ great nephew, Mark Martin, whom the justice had raised since he was 6 years old.

Requests for comment sent Tuesday to Crow’s real estate holdings company and Club for Growth, the conservative anti-tax group he co-founded, did not immediately receive responses.

In earlier statements, Crow and Thomas defended the paid vacations by saying they are close, longtime friends. Crow said they’ve never discussed pending court cases and that he’s unaware of any of his other friends seeking to influence Thomas. 

Thomas said colleagues advised him that he did not have to disclose the travel. He also reportedly believed he did not have to disclose the 2014 real estate sale to Crow because he lost money on the deal but is amending his financial disclosure forms to include it.

On the tuition payments, Crow’s office told ProPublica the billionaire “has long been passionate about the importance of quality education and giving back to those less fortunate, especially at-risk youth,” adding, “he and his wife have supported many young Americans through scholarship and other programs at a variety of schools.”

The Senate Judiciary Committee held a hearing last week in which lawmakers debated the possibility of Congress passing an ethics reform bill for justices. The Supreme Court currently polices itself on ethics matters.

Democrats on the committee argued that legislation would boost public confidence in the high court. Republicans, who accused Democrats of continuing a campaign to delegitimize the court in response to rulings they did not like, argued such a bill would violate the Constitution’s separation of powers provision. But legal experts who testified were divided. 

In an interview on ABC's "The View" on Tuesday, Minnesota Sen. Amy Klobuchar, a Democrat on the panel, lamented what she called a "loss of trust" in the Supreme Court amid the spate of ethics questions.

"You don't want to have that happen," she said. "You want to have people trust that they're making decisions based on the law."

"There's all kinds of problems right now [with the court]," she continued. "And so if they want to at least up the trust, that they're not making decisions based on billionaires giving them rides on yachts ... I think that what they need is enforceable ethics rules, and if they're not going to do it themselves, the Congress should pass a law that gives them ethics rules."

Aso last week, The Washington Post reported that judicial activist Leonard Leo arranged for Thomas’ wife, Ginni, to be paid tens of thousands of dollars in consulting fees just before Leo’s nonprofit, the Judicial Education Project, filed a brief to the Supreme Court in a landmark voting rights case and emphasized that the paperwork should have “No mention of Ginni.” Leo has been a key figure in supporting nominees to the court.

Leo said in a statement to The Post the payments to Ginni Thomas were for legitimate work that “involved gauging public attitudes and sentiment.” He said he wanted to keep her name off paperwork because he knew “how disrespectful, malicious and gossipy people can be” and wanted to protect the Thomases’ privacy.