Kagan, former dean of the Harvard Law School, was a finalist when Sonia Sotomayor was appointed by Obama to the court last year. Because she has already been vetted  -- and has won praise from some conservative quarters -  White House sources have stated that she heads Obama's short list of candidates to replace Stevens, the leader of the 4-member progressive bloc of Supreme Court justices.

"When President Obama chose Sonia Sotomayor to replace David Souter, that had very little effect on the ideological balance of the Court, because Sotomayor was highly likely to vote the way Souter did in most cases," Glenn Greenwald, a lawyer and former civil rights litigator, wrote in Salon. "By stark contrast, replacing Stevens with Kagan (or, far less likely, with [Cass] Sunstein) would shift the Court to the Right on a litany of key issues (at least as much as the shift accomplished by George Bush's selection of right-wing ideologue Sam Alito to replace the more moderate Sandra Day O'Connor)."

No one claims that Kagan, who supports abortion rights and gay rights, is a conservative. However, she is more likely to vote with the court's conservative wing on such issues as executive power and civil liberties.

Candidates favored by progressives include Appellate Court Judge Diane Wood, former Yale Law School dean and current State Department legal adviser Harold Koh and Stanford Law professor Pamela Karlan. The only African-American mentioned has been former Georgia Supreme Court Chief Justice Leah W. Sears, who is considered a long-shot. Attorney General Eric Holder should be added to the list of serious candidates.

Writing in the Nation, Ari Melber said, "With Justice Stevens retiring, it will take a nominee like Harold Koh just to maintain the Court's status quo."

Greenwald predicts that Obama's next appointee will be more conservative than Stevens.

"The danger that we don't have such a status-quo-maintaining selection is three-fold," he wrote. "(1) Kagan, from her time at Harvard, is renowned for accommodating and incorporating conservative views, the kind of 'post-ideological' attribute Obama finds so attractive; (2) for both political and substantive reasons, the Obama White House tends to avoid (with few exceptions) any appointees to vital posts who are viewed as 'liberal' or friendly to the Left; the temptation to avoid that kind of nominee heading into the 2010 midterm elections will be substantial... and (3) Kagan has already proven herself to be a steadfast Obama loyalist with her work as his Solicitor General, and the desire to have on the Court someone who has demonstrated fealty to Obama's broad claims of executive authority is likely to be great."

The most disturbing aspect of a possible Kagan appointment is her admiration of the Federalist Society, a network of conservative and libertarian students, law professors, attorneys and judges whose goal is to advance the conservative agenda by pushing America's legal system to the right.

Five of the nine members of the Supreme Court --- Chief Justice John Roberts, Samuel Alito, Clarence Thomas, Antonin Scalia and Anthony M. Kennedy - have been members or close affiliates of the Federalist Society. Federalist board members have included Orin Hatch (R-Utah), one of the most conservative members of the Senate; Ed Meese, attorney general under Ronald Reagan; and C. Boyden Gray, President George H.W. Bush's chief White House counsel.

The group is so influential that in 2001 George W. Bush discontinued the practice, dating back to Dwight Eisenhower, of presidents relying on the National Bar Association to vet judicial appointments. Under Bush, the Federalist Society served that function for judgeships and some cabinet positions..

In an article Trevor Coleman and I wrote on the Federalist Society for Emerge magazine in October 1999, titled "Hijacking Justice," Francis A. Boyle, a law professor at the University of Illinois, said: "...They want to go beyond getting rid of affirmative action. They want to go back to Brown v. Board of Education."

Boyle noted that in a lecture at Columbia University, Scalia said if the landmark school desegregation case came before him today, he would vote against the plaintiffs, which would have the effect of maintaining segregated schools.

At a reception for the Federalist Society at Harvard, members gave Kagan a standing ovation.

One Federalist Society site carries this quote from her: "I love the Federalist Society...They are highly committed, intelligent, hard-working active students who make the Harvard community better."

Other conservatives seem to love Kagan as much as she loves the Federalist Society.

Eric Lichtblau began a May 17, 2009 story in the New York Times: "When Elana Kagan went before the Senate Judiciary Committee in February as President Obama's nominee for solicitor general, Republicans were almost as effusive as Democrats in their praise for her."

The story continued, "...Indeed, there was so much adulation in the air from Republicans that one Democrat, Amy Klobuchar of Minnesota, joked at the hearing that she understood how Ms. Kagan 'managed to get a standing ovation' from the Federalist Society, a conservative legal group."

But appointing Kagan because she might be easier to confirm would be a major mistake. President Obama should appoint someone in the mold of Thurgood Marshall, William O. Douglas and William J. Brennan.

Many people voted for Obama with the expectation that he would appoint progressive judges to the bench. To do anything less, especially to placate conservatives, would be a betrayal of trust.

George E. Curry, former editor-in-chief of Emerge magazine and the NNPA News Service, is a keynote speaker, moderator, and media coach. He can be reached through his Web site, www.georgecurry.com You can also follow him at www.twitter.com/currygeorge.

 READ MORE COLUMNS BY CURRY