Washington (CNN) -- As reaction mounted to Supreme Court Justice John Paul Stevens' announcement that he will retire from the high court this summer, members of both parties drew lines over the upcoming battle to replace him.
"Justice Stevens' approaching retirement sets in motion an important constitutional process to nominate and confirm the next associate justice of the Supreme Court," said Alabama Sen. Jeff Sessions, the ranking Republican on the Senate Judiciary Committee. "In exercising its advise and consent role, the Senate must act on behalf of the American people to carefully scrutinize the nominee's qualifications, prior speeches and writings, and record."
Speculation over Stevens retiring had increased in recent months. Government sources tell CNN that the White House has quietly prepared for weeks in anticipation of a vacancy. One senior administration official said that the White House has "about 10" names on the list to replace Stevens. Another said that some on the list have "already been vetted," when they were considered before Justice Sonia Sotomayor was chosen last year.
Administration officials have privately expressed hope that a qualified and well-liked candidate may build political momentum ahead of the November midterm elections.
At an afternoon news conference, President Obama said Stevens' leadership will be missed. As for a nominee?
"While we cannot replace Justice Stevens' experience or wisdom, I will seek someone in the coming weeks with similar qualities," he told reporters in the White House Rose Garden. "An independent mind, a record of excellence and integrity, a fierce dedication to the rule of law, and a keen understanding of how the law affects the daily lives of the American people."
Stevens' vacancy has resurrected memories of last year's Sotomayor confirmation.
Republican opponents raised concerns over her statements and rulings on issues such as gun control, affirmative action and property rights.
They also unleashed tough questions about some of her controversial speeches and statements, including her hope that a "wise Latina woman, with the richness of her experiences" would reach a better conclusion than a white man "who hasn't lived that life."
Sessions said Friday that after Sotomayor's nomination, Americans are rightly "concerned about the future of our judiciary."
"The product of her confirmation hearing was a near-universal rejection of President Obama's empathy standard, the flawed notion that judges should allow personal feelings, political opinions and social views to guide judicial decision making," he added.
Sen. Orrin Hatch, R-Utah, former Judiciary Committee chairman, praised Stevens, saying he has had a "profound impact on the judiciary and the law."
"He is a remarkably dedicated public servant and a profoundly decent human being," he said. "All Americans should thank him for his dedicated service, and we all wish him a happy and healthy retirement."
Hatch hinted that Obama should steer clear of an "activist judge, who would substitute their own views for what the law requires."
It's a point that Senate Minority Leader Mitch McConnell, R-Kentucky, agreed with.
"Americans can expect Senate Republicans to make a sustained and vigorous case for judicial restraint and the fundamental importance of an evenhanded reading of the law."
Sen. Patrick Leahy, D-Vermont, chairman of the Senate Judiciary Committee, noted Steven's "unique and enduring perspective" and his "stalwart adherence to the rule of law." Like his Republican counterparts, Leahy set the tone for what's to come.
"As we move forward with preparations for the second Supreme Court nomination of this Congress, I am reminded of the Vermont marble inscribed above the entrance of the Supreme Court which pledges 'Equal Justice Under Law.' I hope that senators on both sides of the aisle will make this process a thoughtful and civil discourse," he said.
Leahy, who will lead the nomination hearing process before the Senate can take up a confirmation vote, said he expects the president to consult both parties in the process.
"All senators should strive to fulfill their constitutional duty of advise and consent, and give fair and thorough consideration to Justice Stevens' successor."
Senate Majority Leader Harry Reid said Stevens' "strong presence" on the court will be missed. He hoped that Obama would "use the same wisdom that he showed with his nomination of Justice Sotomayor and name a well-qualified successor."
He added: "I encourage my Republican colleagues to join us in conducting fair, respectful hearings and swift confirmation of the President's nominee."
House Speaker Nancy Pelosi, D-California, also heaped praise on Stevens and noted that the next nominee should follow in his footsteps.
"I look forward to the President nominating an individual who carries on Justice Stevens' legacy, who stands for justice, equality, and opportunity for all, and who keeps faith with the Supreme Court's role as a defender of individual rights," she said in a statement.