Liberal members of President Biden’s commission to evaluate potential reform of the Supreme Court pushed back Friday against what they said was an overly negative review of the pros and cons of adding seats to the high court.

The left flank of the Democratic Party is demanding that Congress add justices to restore “balance” to a court that now has six conservatives and three liberals — in part because of Republican maneuvering during the last year of President Barack Obama’s term. Critics say increasing the number of justices would be court-packing, and would set off a tit-for-tat response by whichever political party is in charge.

Draft materials released Thursday by the Presidential Commission on the Supreme Court of the United States indicated a consensus that expanding the court was a legal option, but would bring a host of problems. At a public meeting of the commission on Friday, some said the evaluation went too far.

“Dismissing the most salient and most viable intervention on the table cannot help but send a message that the underlying problem the intervention is trying to address is neither urgent nor serious,” said Harvard law professor Andrew Manuel Crespo. “Suffice to say there are a great many people who disagree with that conclusion, including multiple elected leaders at the federal level, multiple leading scholars, numerous witnesses to our commission, and millions of our fellow citizens.”

Expanding the court would be dramatic, said constitutional law expert Laurence Tribe. At the same time, he added: “Many people, and I include myself in this, believe we are indeed in a ‘break-the-glass’ moment.”

Sherrilyn Ifill, president of the NAACP Legal Defense and Educational Fund, said the report’s discussion dwelt too much on the partisan considerations of adding seats and not enough on the value that could come with additional justices.

“There are reasons that relate to diversity of background and of profession, of race and gender, of geography, of law school,” Ifill said. “There are many reasons why one might support the idea of expanding the court that don’t have to do with your being beholden to a particular partisan agenda or another.”

The commission is not supposed to make recommendations to Biden, but to provide “analysis and appraisal” of the current debate over the Supreme Court, according to co-chair Cristina M. Rodríguez, a constitutional law professor at Yale Law School. She and co-leader Bob Bauer, who was White House counsel under Obama, said the commission’s work was to be driven by concepts such as protecting the court’s legitimacy and independence.

But consensus can be difficult. Two conservatives on the 38-member body — Jack Goldsmith of Harvard Law School and Caleb Nelson of the University of Virginia School of Law — have resigned, the White House acknowledged Friday. “We respect their decision and very much appreciate the significant contributions that they made during the last 5 months in terms of preparing for these deliberations,” White House spokesman Andrew Bates said.

Other conservative members of the group worried that a lengthy discussion of court expansion gave “too much oxygen” to an idea that would upset established norms, in the words of University of Chicago law professor Will Baude. The number of justices changed during the first century of U.S. history, but has been at nine since 1869.

Another topic proved difficult as well. The commission’s preliminary report said term limits for justices, who now have life tenure, “appear to enjoy the most widespread and bipartisan support.”

“The United States is the only major constitutional democracy in the world that has neither a retirement age nor a fixed term of years for its high court justices,” the report said. It said a term of 18 years seemed most popular with those who presented testimony. But there is a big obstacle: Many of those who testified believe the Constitution must be amended to make such a change, a difficult undertaking.

The Constitution holds that justices and federal judges “shall hold their Offices during good Behaviour,” a phrase interpreted to mean for life, as a way to ensure the judiciary’s independence.

But some members said the more they studied the issue, the less they were inclined toward term limits.

Adam White, resident scholar at the American Enterprise Institute and an assistant professor of law at George Mason University’s Antonin Scalia Law School, said he had joined the commission thinking term limits might be a good idea.

But he said he now thinks it could present “profound risks.” A system that would ensure each president gets to make at least two Supreme Court justices could further “expand and entrench” presidential power, he said.

Tribe, too, said he now had a dim view of limits. But he worried that finding fault with each proposal could be “dispiriting in the extreme” to those who think the court needs serious reform.

Biden named the commission in response to liberal demands that something be done to “balance” the court. Liberals were particularly angry that a Republican-controlled Senate refused to hold a hearing on Obama’s nominee to fill the seat of the late Justice Antonin Scalia in 2016.

Four years later, the Senate rushed through the nomination of Amy Coney Barrett to take the seat of the late Justice Ruth Bader Ginsburg even as votes were being cast to deny President Donald Trump a second term.

“Unmistakably, the overall trend over the last three decades has been toward more partisan conflict, which has affected nominations to the lower courts, as well as the Supreme Court,” the draft material says.

The commission is looking at other issues as well.

Unlike other federal judges, Supreme Court justices are not bound by a formal code of conduct. Chief Justice John G. Roberts Jr. has said that all justices consult with the code for lower-court judges in assessing their own ethical obligations. But the report notes that a voluntary system may not be the best approach. “It is not obvious why the court is best served by an exemption from what so many consider best practice.”

A written code of conduct that applies to justices, the report says, “would bring the court into line with lower federal courts and demonstrate its dedication to an ethical culture.”

In several areas, the report suggests ways to enhance transparency and public understanding of the court. When justices decide to sit out certain cases because of personal conflicts, the report says, “statements from the justices explaining their reasons for recusal could enhance transparency of the recusals process,” and those decisions could help guide other justices.

When it comes to potential conflicts, the commission also notes the consensus among court observers that no justices or their spouses or children should own individual publicly traded stocks. On the current court, Roberts and Justices Stephen G. Breyer and Samuel A. Alito Jr. hold stocks.