WASHINGTON -- The tepid concerns expressed last night in response to President Bush's choice of appeals court Judge John G. Roberts Jr. for the U.S. Supreme Court suggested the Senate just might be able to avoid a bruising battle over his nomination.

While liberal groups immediately raised questions about how little is known about Roberts' personal views -- particularly whether he would favor overturning Roe v. Wade, the court decision that made abortion legal -- and conservative groups hailed Roberts as an excellent choice, Democratic senators were cautiously noncommittal.

In the early hours, it appeared that the battle -- if there is one -- may center on how much Roberts is willing to reveal in hearings before the Senate Judiciary Committee later this year.

Conservative groups were clearly pleased with the president's choice. C. Boyden Gray, chairman of the conservative coalition Committee for Justice who was legal counsel to President George H.W. Bush, described the Harvard Law School graduate and former clerk to now-Chief Justice William H. Rehnquist as having had "one of the most distinguished legal careers in modern times."

Manuel Miranda of the Third Third Branch Conference, another major conservative coalition, said Bush's choice had "hit it out of the ball park." Sen. Rick Santorum, R-Pa., called Roberts "a brilliant legal mind and a man of deep character."

On the other side, many liberal groups were scrambling to gather background on Roberts yesterday evening, in part because speculation had centered for much of the day on 5th Circuit Court of Appeals Judge Edith Brown Clement. Many of them pointed out that Roberts' written record may be brief since he has served for only two years on the federal bench.

Nan Aron, president of the liberal Alliance for Justice, said her organization could not support Roberts "at this time," because of "serious concerns about whether he will be fair, independent and will protect the rights and freedoms of all Americans."

Ralph Neas, president of the People for the American Way, said in a statement that he was "extremely disappointed" that the President did not choose "a consensus nominee" in the mold of retiring Justice Sandra Day O'Connor and that Roberts' record "raises serious concerns as well as questions about where he stands on crucial legal and constitutional issues." The abortion rights group NARAL stood out last night in its immediate opposition to Roberts' nomination.

At this early stage, it was difficult to decipher the views of key members of the U.S. Senate, which will decide later this fall whether to confirm or reject Roberts.

Senate Minority Leader Harry Reid of Nevada said Roberts, who received the American Bar Association's top rating of "well-qualified" in 2003, has "suitable legal credentials, but that is not the end of our inquiry. The Senate must review Judge Roberts' record to determine if he has a demonstrated commitment to the core American values of freedom, equality and fairness."

New York Sen. Charles E. Schumer, who voted against Roberts' 2003 appointment to the D.C. Circuit Court of Appeals in the Judiciary Committee, said he opposed Roberts at that time because he didn't answer questions fully and openly during his confirmation hearings.

But Schumer, one of the Senate's most liberal Democrats, said last night there was "no question that Judge Roberts has outstanding legal credentials and an appropriate legal temperament and demeanor." He urged the nominee to be forthcoming during this round of hearings.

When asked where Roberts' nomination would fall between a difficult course toward confirmation and an easy one, Schumer answered "It's somewhere in that broad middle."

After being appointed by Bush in 2003 for the U.S. Court of Appeals, D.C. Circuit, Roberts was confirmed by the Senate by unanimous consent. He had been approved 16-3 in the Judiciary Committee.

In public hearings this fall, many questions from Democrats may focus on his record between 1989 and 1993, when he served as principal deputy solicitor general under President George H.W. Bush.

During that time, Roberts endorsed a legal brief arguing that the Supreme Court should overturn Roe v. Wade. But during the 2003 hearings on his appeals court nomination, Roberts said he considered Roe v. Wade "settled law of the land," adding, "There is nothing in my personal views that would prevent me from fully and faithfully applying that precedent." As a Supreme Court justice, however, he would have more authority to overturn precedent.

Aron of the Alliance for Justice complained last night that in his years as a political appointee in the administrations of Presidents Reagan and George H.W. Bush, Roberts "helped craft legal policies that sought to weaken school desegregation efforts, the reproductive rights of women, environmental protections, church-state separation and the voting rights of African Americans" -- all likely topics for the confirmation debate.

Senate Judiciary Chairman Arlen Specter, R-Pa., who will guide the Senate confirmation process, attended the official announcement at the White House yesterday evening. Speaking to reporters from the White House driveway afterward, he appeared to give Roberts his stamp of approval when he said, "Professionally it would be hard to find someone with better credentials than Judge Roberts." But when asked whether the president had made a safe choice, he was more circumspect.

"I don't know that anything in Washington, D.C. is safe, if it's a nomination," Specter said. "We will listen to him in great detail, but when you review his resume, not many around -- I don't know that there's one in the Senate that can match it."

Sen. Patrick Leahy of Vermont, the Judiciary Committee's ranking Democrat, said that even though Roberts was approved unanimously for the D.C. Circuit Court, the threshold is higher for Supreme Court nominees.

"No one is entitled to a free pass to a lifetime appointment to the Supreme Court," Leahy said.