Washington (CNN) -- Ideology is hard to characterize, particularly in judges who presumably are not disposed to view the law through a strictly political lens.
The term "reliably conservative" or "reliably liberal" may be the best a president can hope for when choosing someone for the Supreme Court, especially the newest member of the bench.
Justice Elena Kagan has no judicial record that conservatives or liberals can easily consider when debating what kind of jurist she will be.
As a White House lawyer and policy wonk in the mid- and late-1990s, she was involved in number of hot-button issues like late-term abortion, gun rights, affirmative action, and tobacco regulation. Memos from her government service reveal a politically pragmatic, cautious lawyer, whose views for the most part mirrored the president's. She comes across as a mainstream liberal, with little desire to passionately argue strong positions on contentious issues.
"I don't think that the left in the United States should expect Elena Kagan to be a kind of flame-throwing, very aggressive liberal," said Thomas Goldstein, a top Washington lawyer and founder of scotusblog.com. "Her reputation-- everything she has done professionally-- is instead of someone who tries to bring people together. She will be in the left, but that's different from being an ideologue. I actually think she will be more successful the way she's going to come at it."
Sources close to her say she has kept a deliberately low public profile since being sworn in August 7. She hired a staff that includes four law clerks, and has been busy in her new chambers on pending appeals. Her colleagues have welcomed her warmly to their ranks.
Those sources say her predecessor John Paul Stevens has been especially impressed, and has reached out to offer personal advice on her transition.
The 50-year-old Kagan has no judicial experience, and sources say she has endured a measure of anticipation and nervousness over how quickly she will fit in with the court's unique customs and rhythms.
Her learning curve will be further slowed because she will recuse herself from at least 24 cases already on the docket. That means she will not sit in oral arguments or vote on the outcome.
As the former Solicitor General in the Justice Department, it was her job to supervise all pending appeals at the high court, and she has withdrawn from those cases in which she was involved or which might present a conflict-of-interest.
President Barack Obama and fellow liberals certainly hope Kagan will rule much like Stevens, who until retiring in June, had become the undisputed leader of the court's unofficial liberal wing.
But such choices can backfire. Take the case of Earl Warren. He was California's governor and a rival of Dwight Eisenhower in the presidential primaries of 1952. Warren eventually dropped out of the race and threw his support to the retired general.
As political payback and to court Western conservatives, Ike selected Warren as chief justice in 1953, despite his lack of judicial experience.
Warren's once-conservative views soon moderated, and under his leadership, the Supreme Court established a lasting liberal record, particularly in civil rights, due process and individual protections. Eisenhower later called the selection "the biggest damn-fool mistake I ever made."
Conservatives expressed similar concerns about other justices named by Republican presidents who they later termed "disappointments," including Stevens, David Souter, William Brennan, and Harry Blackmun.
Unlike most past presidents, Democrat Obama has called on his experience as a constitutional law professor to spell out the kind of justice he expects to see, using "empathy" as a key barometer.
"I will seek somebody with a sharp and independent mind and a record of excellence and integrity," Obama said in May 2009, just before he chose Justice Sonia Sotomayor for the high court. "I will seek someone who understands that justice isn't about some abstract legal theory or footnote in a case book; it is also about how our laws affect the daily realities of people's lives-- whether they can make a living and care for their families, whether they feel safe in their homes and welcome in their own nation."
Obama has cited Ruth Bader Ginsburg and Stephen Breyer as two justices he admires. And Sotomayor in her first year has carved out a steady progressive record, much in step with Stevens, Ginsburg, and Breyer.
As for Kagan, some left-leaning groups remain worried she could prove to be someone not as advertised. Her views on executive authority in particular have raised some eyebrows. As chief defender of the administration's anti-terror strategy, Kagan has articulated a more robust defense of the White House than many civil rights and human rights groups would like.
"There's a real concern about Kagan with respect to national security issues," said Vincent Warren, executive director of the Center for Constitutional Rights, which has defended dozens of prisoners held at the military prison at Guantanamo Bay, Cuba. "We do know from how she addressed the issue at her confirmation proceedings, and I certainly can't see anything that would lead me to believe that she would have a less expansive version of what executive power is than certainly the current form, and certainly with respect to how George W. Bush viewed it. So I think there's a real concern for human rights groups."
Warren's group wonders whether as a justice, Kagan "might go with what the Obama administration and what the Bush administration had put in play rather than seriously challenging that."