John Paul Stevens didn’t really break any news when he revealed this weekend that he would retire sometime within Barack Obama’s term. Thoughts of retirement and being 89 years old go together, and anyway Stevens hasn’t hired enough law clerks for the next court session. What is new is the speculation on replacements for Stevens, which has settled on the Solicitor General and two federal appeals court judges.

The White House has declined to comment on its preparations for selecting a successor, but those close to the process repeatedly have mentioned three names as likely to merit close consideration.

One is Mr. Obama’s solicitor general, Elena Kagan, a former dean of Harvard Law School who was considered for the nomination that ultimately went to Justice Sonia Sotomayor [...]

Liberals see a surer voice in another finalist for last year’s vacancy, Judge Diane Wood of the Seventh U.S. Circuit Court of Appeals in Chicago. On a court known for its intellectual heft, Judge Wood has proven a serious counterweight to such influential conservative judges as Richard Posner and Frank Easterbrook, legal observers say [...]

A third oft-mentioned name is Judge Merrick Garland of the U.S. Court of Appeals for the District of Columbia Circuit.

As a Justice Department official in the Clinton administration, Judge Garland oversaw investigations into the Oklahoma City federal building bombing and the Unabomber, Theodore Kaczynski.

I think the typical liberal reaction to these names would be “Huh,” but one informed in legal matters would prefer Wood, be wary of Kagan’s views on executive power (though she was generally fulfilling her duties as Solicitor General in that capacity) and be cool toward Garland.

Dylan Matthews is right to say that none of these picks would alter the ideological makeup of the Court, but I’m not sure that’s in the cards. There are a few judges and legal scholars out there, like Pam Karlan and Kathleen Sullivan, who would actually represent that rare constituency on the Court these days, liberals, but the GOP clearly wants to filibuster Obama’s next nominee, and with those above they would lock arms together and do so. Anyway, we have a President disinclined to pick high-profile fights. Wood represents probably the leftward edge of this selection.

I would say that just replacing judges, even if they fall in the same broad ideological category, has an impact on the Court. Sonia Sotomayor and whoever Obama picks to replace Stevens will sit on the bench for 20 years or more, anchoring the center-left spots. John Roberts replaced William Rehnquist, not changing the disposition of the Court to a great degree, but he lengthened the hold of the Chief Justice from a conservative perspective for a couple more decades. If Obama makes three appointments, even if they do nothing in the near term, they could have long-term effects.