Kagan Nomination to Supreme Court Heads to Senate as Dems Predict Confirmation

President Obama's nomination of Elena Kagan to be the 112th justice on the U.S. Supreme Court was met today with praise from Democrats and cautious skepticism from Republicans, who promised a vigorous election-year debate on judicial philosophy.

While most experts believe Kagan will face a relatively quick path to the bench, her nomination sets the stage for summer Senate confirmation hearings that are expected to showcase the political parties' ideological divide.

VIDEO: Barack Obama Selects Elena Kagan as His Supreme Court NomineePlay

At least one Republican senator, Jim Inhofe of Oklahoma, has already pledged to oppose Kagan's nomination partly because of what he calls "her lack of impartiality when it comes to those who disagree with her position."

Obama praised Kagan earlier today as someone who would make an "outstanding justice" as the replacement for retiring Justice John Paul Stevens, saying she embodies the same ideals of "excellence, independence, integrity and passion for the law" as held by the court's most liberal stalwart.

VIDEO: Politicians React to Elena Kagans NominationPlay

"She's a trailblazing leader," Obama said. "The first woman to serve as dean of Harvard Law School and one of its most successful and beloved deans in its history. And she is a superb solicitor general, our nation's chief lawyer, representing the American people's interests before the Supreme Court. The first woman in that position as well."

If confirmed, Kagan, 50, will also become the fourth woman ever to sit on the nation's highest court and mark the first time three women have shared the bench at once.

Video of Obama announcing Elena Kagan as nominee for Supreme Court.Play
Obama Announces Elena Kagan as Supreme Court Nominee

Obama praised Kagan's record of achievement as a lawyer and legal scholar and ability to win the praise of peers from across the aisle through her openness to diverse legal viewpoints.

"Her habit -- to borrow a phrase from Justice Stevens -- of understanding before disagreeing, her fair-mindedness and skill as a consensus builder" has won her respect and admiration, Obama said.

For her part, Kagan said she is humbled by the nomination and honored to be following in Stevens' footsteps.

"The court is an extraordinary institution," she said, "in the work it does and the work it can do for the American people, by advancing the tenets of our Constitution, by upholding the rule of law, and by enabling all Americans regardless of their background or their beliefs to get a fair hearing and an equal chance at justice.

SLIDESHOW: Elena Kagan Through the Years

"Mr. President, I look forward to working with the Senate in the next stage of this process, and I thank you for the honor of a lifetime."

Democrats Expect Kagan Confirmation by August

Under the Constitution, the Senate must confirm the president's nominations to the Supreme Court, a process that begins with hearings on the nominee's background and qualifications in the Judiciary Committee, which are expected to be held in July.

Sen. Patrick Leahy, the Vermont Democrat who chairs the committee, said today in no uncertain terms that he believes the administration's pick will reach the bench before the next term starts in October.

VIDEO: Supreme Court Nominee Elena KaganPlay
Who Is Elena Kagan?

"She will be confirmed," Leahy said enthusiastically, praising Kagan for her experience outside the so-called "judicial monastery" from which most Supreme Court justices have hailed.

"The Senate has adequate time to thoroughly review Ms. Kagan's impressive qualifications and academic writings, as well as her court filings and oral arguments while she has served the national as solicitor general, and consider her nomination this summer," he said.

After the hearings, the full Senate will consider Kagan's confirmation, and even though Democrats fall one vote short of the 60 needed to prevent a Republican filibuster, most experts believe the chances of that are slim.

But Senate Majority Leader Mitch McConnell of Kentucky today refused to rule it out. "It's way too early to be making a decision about the issue of whether there should be a 60-vote threshold on the nominee," he said on ABC's "Top Line."

VIDEO: Majority of Republicans voted "no" on Elena Kagan for solicitor general.Play
Elena Kagan's Confirmation Battle

Kagan was confirmed by the Senate as solicitor general last year with the support of seven Republicans, including two conservatives on the Judiciary Committee: Sens. Jon Kyl and Orrin Hatch.

Democrats will likely make the case in the weeks ahead that if she's good enough to represent the United States before the Supreme Court, she's good enough to be on the court.

Republicans to Scrutinize Kagan, Showcase Philosophical Differences

Still, the overwhelming majority of Republicans voted "no" on Kagan for solicitor general and some are now expressing skepticism about her lack of judicial experience and controversial views, including her decision as dean of Harvard Law School to block military recruiters from campus because of the services' ban on openly gay and lesbian members.

"She is a surprising choice from a president who has emphasized the importance of understanding 'how the world works and how ordinary people live,'" said GOP Sen. John Cornyn of Texas. "Ms. Kagan has spent her entire professional career in Harvard Square, Hyde Park, and the DC Beltway. These are not places where one learns 'how ordinary people live.'"

McConnell also questioned Kagan's lack of judicial experience. "She's the least qualified [nominee] in terms of judicial experience in 38 years," he said. "Some would argue that maybe we need to have people who don't have judicial experience. I saw a survey indicating about 70 percent of the American people think judicial experience is a good idea for somebody who's going to be on the Supreme Court."

Some Republicans 'Open' to Kagan on Bench

Utah's Hatch, one of the seven Republicans who supported Kagan for solicitor general, cautioned that his vote then does not necessarily mean his support now but said he's keeping an open mind.

"My conclusion will be based on evidence, not blind faith," Hatch said. "Her previous confirmation, and my support for her in that position, do not by themselves establish her qualifications for the Supreme Court or my obligation to support her."

Arizona's Kyl, who also supported Kagan for her current post, agreed. "A temporary political appointment is far different than a lifetime appointment to the Supreme Court," he said.

Some key Republicans on the Senate Judiciary Committee offered more upbeat first assessments of the nominee today, though careful to reserve endorsement until a more thorough review.

Sen. Lindsay Graham of South Carolina said he is "generally pleased" with the job Kagan has done as solicitor general, "particularly regarding legal issues related to the war on terror."

Sen. Susan Collins of Maine praised Kagan's "impressive resume of dedicated public service," while fellow Mainer Sen. Olympia Snowe embraced her "strong intellectual credentials."

Kagan supporters say they expect at least some Republicans to support her confirmation, and any criticism leveled by those who don't will not pose a real threat to her confirmation.

"You don't have to have judicial experience to be a highly qualified candidate," former Obama White House counsel Greg Craig said. "She is her own person, an independent force of nature."

William Rehnquist and Lewis Powell, both appointed by President Richard Nixon in 1972, were the last two justices to sit on the high court without any prior judicial experience.

ABC News' Jake Tapper contributed to this report.