WASHINGTON — In the aftermath of ethics questions emerging around Justice Clarence Thomas and a series of politically charged rulings, a coalition of more than 30 progressive groups plans to initiate next week a new nationwide campaign calling for structural changes to the Supreme Court.

The effort will include progressive leaders and organizations that have not previously been engaged in the push to overhaul the court, including by imposing term limits on justices or increasing their numbers. But leaders of the organizations say they now see the need to spur a larger public discussion about the role of the court in American life.

“This is new to us,” said Mini Timmaraju, the president of NARAL Pro-Choice America. She said her organization’s decision to join the campaign was driven in part by recent court decisions on abortion rights, gun control and other issues that run counter to well-documented public opinion.

“We feel a special obligation to jump in now,” she said. “It feels the time is right to start having this conversation about expansion. Everything has to be on the table.”

Those taking part in the “Just Majority” drive, with the theme “democracy demands a fair and ethical court,” say one goal is to motivate voters to make the direction of the court part of their calculation in next year’s elections. The organizations participating are active on abortion rights, gun control, voting laws, civil rights, racial justice and the environment, along with more traditional judicial advocacy groups.

The campaign kicks off on Monday in Boston, the first city in a 20-stop nationwide bus tour, and is scheduled to end in late June in Washington. Democratic lawmakers are expected to make appearances along the way, beginning in Boston with Senators Elizabeth Warren and Edward J. Markey and Representative Ayanna S. Pressley, all of Massachusetts.

The effort follows new disclosures about Justice Thomas’s unreported financial ties to a billionaire Republican donor as well as evidence of the court’s declining credibility with the public after overturning Roe v. Wade and other decisions.

“The revelations about Clarence Thomas are extremely upsetting,” said Cecile Richards, the former head of Planned Parenthood, who will be taking part in the campaign. “For years, Republicans have made the court an issue. I think it is time that Democrats actually talk to voters about what is going on.”

In the case of Justice Thomas, he has said he intends to revise his financial disclosures to reflect his relationship with the donor, Harlan Crow, who has provided extensive travel for the justice and also purchased property in Georgia that Justice Thomas owned and where his mother lives, according to reports by ProPublica.

The Senate Judiciary Committee is scheduled to conduct a hearing in the next few weeks exploring the disclosures about Justice Thomas as well as considering longstanding demands that the court adopt a more stringent set of ethics guidelines and disclosure requirements.

Republicans have so far dismissed the Democratic efforts and say they believe the court is fully capable of taking care of any issues it might have.

“I have total confidence in the chief justice of the United States to deal with these court internal issues,” Senator Mitch McConnell, Republican of Kentucky and the minority leader, said on Tuesday in response to questions about Justice Thomas. He suggested that the attacks by Democrats were in response to rulings they opposed.

After Mr. McConnell blocked President Barack Obama from filling a court seat for nearly a year in 2016, progressive activists who then watched President Donald J. Trump name three justices to the court began clamoring for a new approach, including a larger court.

Under pressure from the left, President Biden created a 34-member commission of legal experts and academics to study various proposals to change the court, including enlarging it and establishing term limits. Mr. Biden himself expressed reservations about pursuing significant changes to the court and the final report by his commission reflected that view, analyzing the proposals rather than recommending any significant revisions.

Some former members of the commission who disagreed with that approach will participate in the bus tour. Organizers say the court continues to provide ammunition for its critics with persistent ethical issues and contentious decisions.

“It continues to invite more people into our struggle and it will put more fuel not just in our bus, but in our message to fight,” said Rashad Robinson, the president of Color of Change, a civil rights advocacy group taking part.

In a mission statement, those organizing the new campaign said that “an unaccountable, unethical majority on the Supreme Court is behaving as if the rules don’t apply to them.”