Before David Souter’s confirmation hearings in the summer of 1990, he so worried conservatives that White House Chief of Staff John Sununu had to mount a last-minute campaign assuring them that the New Hampshire judge would be a reliable vote for the right. During his testimony, Souter frustrated Republican Sen. Charles Grassley by telling him that “courts must accept their own responsibility for making a just society.”

Sonia Sotomayor hasn’t rattled liberals in quite the same way, but she, like Souter, didn’t spend much time at the confirmation hearings defending her nominating party’s judicial philosophy. Is there any chance these two tight-lipped jurists could share a propensity for disappointing their supporters?

Probably not, legal scholars say. What Sotomayor said during her confirmation “would not disable or disqualify her from taking a bolder position or a more progressive position if and when she becomes a justice,” said Robert O’Neil, who clerked for Justice William Brennan and is founding director of the Thomas Jefferson Center for the Protection of Free Expression at the University of Virginia.

Some legal experts attribute the surprise surrounding Souter’s leftward drift to his scant record on the federal bench. Most of his judicial career at that point had been in the New Hampshire state system. He spent a fleeting two months at the federal appellate level before George H. W. Bush nominated him to the high court in July 1990.

Jeffrey Segal, political science professor at Stony Brook University, noted that state courts don’t address constitutional law as often as federal courts. Christopher Eisgruber, the provost of Princeton University, who recently wrote a book about the high court confirmation process, said that state level judicial records can be “harder to read” than federal ones.

Unlike Souter, Sotomayor has had 17 years on the federal bench — six on the trial level in New York and 11 on the 2nd Circuit. That leads some experts to predict her votes on the high court will reflect, to at least some degree, the way she ruled while on the appellate bench. Segal predicts that she will be less liberal than Ruth Bader Ginsburg, more in line with Stephen Breyer. “She will start out as a moderate liberal, and what happens over time is anyone’s guess,” he said.

But conservatives worry that Sotomayor could become “unleashed” as an extreme liberal once on the court, following the pattern of her predecessor.

In his questioning of Sotomayor, Grassley referred back to a statement Souter made that courts must step in to fix social problems when other branches won’t, because “the law of nature and political responsibility, constitutional responsibility, abhor a vacuum.”

“I’ve regretted my vote to confirm him ever since,” Grassley said later, in his statement announcing that he would vote “no” on Sotomayor. “So I’ve asked several Supreme Court nominees about courts filling vacuums at their hearings. Judge Sotomayor’s lukewarm answer left me with the same pit in my stomach that I’ve had with Justice Souter’s rulings that I had hoped to have cured with his retirement.”

On the other hand, Sotomayor’s repudiation of Obama’s empathy standard, among other comments at the hearings, worried some liberal scholars. Doug Kendall, founder and president of the progressive Constitutional Accountability Center, said he was surprised that the nominee so “forcefully distanced herself from” the president’s standard. “I thought she needed to, and would, explain that empathy could come into play only in service of the rule of law, not instead of it,” Kendall said.

Nonetheless, that hasn’t stopped his organization from enthusiastically backing her confirmation, much as Republicans eventually lined up behind Souter. “Republicans, though concerned by Souter’s seeming embrace of the liberal Warren Court ideology, could not abandon a man the White House had assured them was a reliable conservative,” noted ABC News legal correspondent Jan Crawford Greenburg in her 2007 book Supreme Conflict. “Some assumed Souter was simply pandering to Democrats to get through the committee, and they refused to believe he meant what he said.”

But in the end, Sotomayor’s long judicial record, coupled with the increased politicization of the Supreme Court confirmation process, suggests she is not likely to make Souter’s drift in reverse — indeed, experts question how likely such a turn could be in today’s process. Unlike Sotomayor, Souter had few public speeches to comb through for potentially controversial statements. Administrations now seek nominees with long records on the federal bench. And the increased attention on Supreme Court nominees pushes them — regardless of party — to downplay any judicial philosophy they may have embraced before their hearings.

The confirmation process itself, more often than not, says little about a judge’s time on the bench. “It’s impossible to say for sure what’s going to happen with any Supreme Court nominee,” Eisgruber said. “To some extent, we’re going to have to wait and see.”