Washington (CNN) A landmark Supreme Court opinion that bans segregation in public schools took center stage at the Senate Judiciary Committee on Thursday as senators gathered to discuss two of President Donald Trump's judicial nominees who declined to say in their testimony whether the opinion was correctly decided.

The hearing came on the 64th anniversary of the release of the opinion, Brown v. Board of Education, but the final vote for the nominees has been rescheduled for next week, according to a spokesperson for ranking minority member, Sen. Dianne Feinstein of California.

Leaders of major civil rights organizations were in the audience as the senators debated — at times heatedly — what kinds of questions nominees could be "excused" from answering.

Democrats accused the President of pushing forward nominees who are outside of the mainstream. They pointed out that others — like Chief Justice John Roberts and Justice Anthony Kennedy — both testified in their own confirmation hearings that Brown was correctly decided.

"It's an easy question," Feinstein said.

"What does it say about a nominee" that could not say "clearly and unambiguously" that Brown v. Board of Education was correctly decided? she asked.

But Republicans suggested the Democrats are engaged in a ploy meant to smear the names of nominees who were simply following the rules of judicial ethics meant to ensure impartiality.

"I speak for all my colleagues when I say there is no question that this opinion was correctly decided," said Committee Chairman Chuck Grassley, who called it "very unfair and simply inaccurate" to suggest the nominees "somehow disagree with Brown."

Grassley said the nominees should not be forced to label Supreme Court decisions as "correct" or "incorrect" and jeopardize their impartiality.

His colleague Sen. Mike Lee, R-Utah, took the debate a step further saying that it is "disputed nowhere" that Brown is correct. He said to suggest otherwise is "absurd" and "preposterous" and "borders on accusing someone of racism."

Before adjourning without a vote, Democratic Sen. Dick Durbin of Illinois held firm.

"If we can't ask them basic questions about Supreme Court decisions, why are we here?" he asked.

Sen. Kamala Harris, D-California, said she found the testimony "deeply troubling." And Feinstein suggested Democrats are planning, in the future, to do more to push back on the President's nominees.

The dispute comes as the Trump administration continues to break records in the pace of confirming nominees, in order to fulfill the President's stated goal of reshaping the judiciary.

So far, the Senate has confirmed 39 judicial nominees: Neil Gorsuch for the Supreme Court, 21 appeals court nominees and 17 district court judges.

One of the nominees, Wendy Vitter, is up for a seat on the US District Court for the Eastern District of Louisiana.

At her confirmation hearing in April, Sen. Richard Blumenthal, a Connecticut Democrat, asked her about Brown v. Board of Education. Vitter said she didn't mean to be "coy" but that she would get into a "difficult, difficult area when I start commenting on Supreme Court decisions -- which are correctly decided and which I may disagree with."

She went on to say that if she were confirmed, she would be "bound by Supreme Court precedent."

The answer outraged her critics, who noted that Chief Justice John Roberts and Justice Neil Gorsuch had both answered the question during their confirmation hearings.

Vitter serves as the general counsel of the Roman Catholic Archdiocese of New Orleans and is married to Louisiana's former Republican Sen. David Vitter, who was implicated in the sex scandal concerning the so called "DC Madam" back in 2007.

Conservatives are crying foul, arguing Vitter declined to answer the Brown question because she believes that judges should maintain their impartiality by declining to put forward personal opinions on particular cases.

They point to Vitter's testimony later in the hearing, when Sen. John Kennedy, a Louisiana Republican, asked the question a different way.

"I am not asking about precedent," he said. "I just want to know about what you think about the social policy of having schools, Ms. Vitter, segregated by race, even if they are equal. Can we agree that is immoral?"

Vitter said, "Yes."

"As many nominees have done, Vitter simply took the position that it was improper for her to comment on the rightness or wrongness of any particular Supreme Court precedent," said conservative Ed Whelan of the Ethics and Public Policy Center. Whelan says Vitter was avoiding a "slippery slope" of judicial nominees commenting on precedent.

"Sen. Blumenthal has shown that he is eager to race down that slippery slope," Whelan said.

Andrew S. Oldham, who currently serves as general counsel to Texas Gov. Greg Abbott, is a nominee up for a seat on the powerful 5th US Circuit Court of Appeals. He told Blumenthal that "even the most universally accepted Supreme Court case is outside the bounds of a federal judge to comment on."

Oldham went on to say that Brown corrected "an egregious legal error" by overturning the legal policies established in Plessy v. Ferguson back in 1896 and it "abolished segregation in public schools."

But Blumenthal persisted on Brown, asking: "Was it correctly decided in terms of what you know?"

Oldham held firm and noted that Justice Ruth Bader Ginsburg also believed a nominee should not talk about precedent:

"The canons of conduct and the line that was articulated by Justice Ginsburg when she sat in this chair before this committee, where she said that her role as a nominee was to give 'no hints, no previews and no forecasts,' applies just as much to me."

"When inferior court judges come before this committee with a list of cases that they like and a list of cases that they don't, it turns the structure of Article III of the Constitution on its head," he said.

After a pause, Blumenthal responded, "I can't believe that you just gave me that answer."

Oldham's critics note that Ginsburg supplied the committee with thousands of pages of her writings as a law teacher and lawyer and opinions from her time on the US Court of Appeals for the District of Columbia Circuit.

"Oldham, on the other hand, has spent his comparatively short career fighting legal rights and protections for everyday Americans," said critic Nan Aron of the progressive Alliance for Justice.

At 39 years old, Oldham, a former clerk to Justice Samuel Alito, could serve on the bench for dozens and dozens of years.

Carrie Severino of the conservative Judicial Crisis Network believes the Democrats are lashing out in response to Trump's judicial success.

"Democrats know exactly what the standard is at confirmation hearings, that nominees can't comment on cases likely to come before them," she said.

"Justice Ginsburg famously refused to answer multiple questions, as did Justice Gorsuch, and even the late Justice Scalia refused to answer questions about the Marbury v. Madison decision that established judicial review, " she said.

.@SenateMajLdr welcomed @realDonaldTrump to @uscapitol today just after #Senate approved the 21st Circuit Judge. Nearly 1/8 of the nation's circuit judges have been appointed by @POTUS & confirmed by @SenateGOP. This is a monumental achievement of unified Republican government. pic.twitter.com/F8VDjerDmW — Sen. McConnell Press (@McConnellPress) May 15, 2018

Republicans like Severino praise Senate Majority Leader Mitch McConnell for his role in pushing through judicial nominees.

The Kentucky Republican tweeted on Tuesday the Senate had confirmed the President's 21st appellate court nominee and called the action "a monumental achievement of unified Republican government."

Christopher Kang, who serves as chief counsel for a liberal group called Demand Justice, believes McConnell is changing the rules and traditions in the Senate and that all of Trump's nominees should be opposed. There has been a dispute, for instance, over whether nominations should go forward without the approval of both of the nominee's home state senators.

"These are lifetime appointees, and Democrats need to stop treating this as business as usual, "he said.

But Grassley -- the chair of the Judiciary Committee -- is showing no signs of slowing down.

In a recent interview with talk show host Hugh Hewitt, Grassley outlined his plans for the coming months. He noted there are still about 30 district court judicial nominations he wants to push through.

"I have pleaded with McConnell to work nights, to work Saturdays and weekends, and put the pressure on the Democrats," Grassley said.

"We've got to have every Republican around and even cancel a recess so we can clear the calendar of these important nominees," he said.