The US supreme court has been “captured and corrupted by money and extremism”, provoking a “crisis of legitimacy” that threatens the stability of American democracy, warned the representative Alexandria Ocasio-Cortez.

Speaking during a round table on Capitol Hill, the New York Democrat accused the court of “delegitimizing itself through its conduct”.

In the two years since the court overturned Roe v Wade, eliminating the constitutional right to abortion, a decision that sparked fierce political backlash from voters across the ideological spectrum, the court has been rocked by ethics scandals involving two of the bench’s most conservative justices, Clarence Thomas and Samuel Alito.

Related: Trust in US institutions has ‘never been lower’ – here’s why that matters

“The highest court in the land today has the lowest ethical standards,” said Jamie Raskin, a Democratic congressman from Maryland, and the ranking member of the House oversight hearing who joined Ocasio-Cortez in convening the hearing.

Together they sought to “connect the dots” between what they described as a web of dark money and the events that led to a conservative super-majority, cemented by Donald Trump. Only Democrats attended.

“Dark money is the rot in our democracy right now,” said Sheldon Whitehouse, a senator and longtime crusader against secret spending in politics and an advocate of supreme court reform, who appeared as a witness.

Last week, Thomas officially disclosed that he had taken luxury vacations to Indonesia and a retreat in California paid for by the conservative billionaire, Harlan Crow. The Republican mega-donor also paid private school tuition for Thomas’s grandnephew, ProPublica reported as part of a blockbuster series of revelations about the supreme court justices that won a Pulitzer Prize for public service.

ProPublica also reported that Alito flew on a private jet and vacationed with a billionaire who had business before the court. The conservative justice was already under scrutiny following a report in the New York Times that his wife flew an upside-down US flag outside his home in Virginia days after the attack on the US Capitol by extremist Trump supporters, as well as an Appeal to Heaven flag associated with Christian nationalism that flew outside a beach home in New Jersey.

In response to the flag incidents, Democrats in Congress have called for Alito to recuse himself from cases involving Trump and January 6 defendants.

He declined.

Democrats have also introduced a myriad of bills such as one to establish an independent ethics office and internal investigations counsel within the supreme court. Other ideas include limiting the justices to 18 year-terms rather than lifetime appointments and expanding the seats on the court. But reforms are unlikely to happen without Republicans, who have spent decades building the court’s conservative majority.

Thomas has also declined calls to recuse himself from cases involving Trump because his wife, Ginni, a well-known conservative activist, supported the former president’s false claims of election fraud and helped lead the campaign to overturn the results of the 2020 election.

The sustained scrutiny prompted the court to adopt its first code of ethics last year, but it lacks any form of enforcement. Public confidence in the court has plummeted to near historic lows.

Ocasio-Cortez questioned why justices aren’t subject to the same ethical standards as the branches of government. As an example, she said members of Congress are prohibited from accepting gifts valued at more than $50.

“Americans are losing fundamental rights in the process, reproductive health care, civil liberties, voting rights, the right to organize clean air and water because the court has been captured and corrupted by money and extremism,” she said.

Without a binding code of conduct, Raskin said, there was nothing to reign in the justices.

“If you can decide presidential elections with five or four votes in Bush v Gore, if you can pack, stack and gerrymander, not just Congress, but the supreme court itself by denying the other party even a hearing, why can’t you have some friend of the court – some amicus curiae – fly you to Bali for vacation, or pay for your family member’s private school tuition or buy you a recreational vehicle or send you on a lavish, all-expense paid vacation, why the hell not?”