The movement is much diminished from four years ago under President George W. Bush, when Supreme Court vacancies last arose and conservatives marshaled their forces to champion his nominees. (Judge Richard Posner, a prominent Reagan appointee, wrote recently that the conservative movement suffers from “intellectual deterioration.”) Republicans have lost control of the White House and Congress, have no clear party leader and have received low approval ratings.

And some leading groups are having budget woes. Focus on the Family, a Colorado-based evangelical group led by the semi-retired James C. Dobson, rallied social conservatives in support of Mr. Bush’s judicial nominees, but it recently cut more than 200 jobs.

The conservative movement is sharing its resources as it prepares for the nomination. The Judicial Action Group, founded in 2006 and based in Alabama, has organized a research network  dubbed the Supreme Court Review Committee  of about 15 “pro-family ministries” and conservative legal groups, said Phillip Jauregui, president of the group.

Legal analysts with liberal groups, which have also set up a shared research pool, said they were confident that any effort to cherry-pick cases to portray an Obama nominee as radical would fail. “I think the mood and the politics of the country have passed them by,” said Nan Aron, the president of one of the groups, the Alliance for Justice. “It’s not going to work.”

Leaders of both factions say they expect Mr. Obama to appoint a woman. While conservatives have gathered files on three dozen people, for example, all 10 for whom they have made one-page summaries are women: Judge Sotomayor, Judge Wood, Johnnie Rawlinson, Kim Wardlaw and Ann Williams, all federal appellate judges; Martha Vasquez, a federal district judge; Solicitor General Elena Kagan; Beth Brinkmann, a former assistant solicitor general; Leah Ward Sears of the Georgia Supreme Court; and Ms. Sullivan, of Stanford.

Those summaries suggest that conservatives find some potential picks to be less objectionable than others.

The memorandum on Judge Wardlaw, for example, approvingly notes cases in which she voted to deny an appeal in a death penalty case, to allow a city to display a Ten Commandments monument, and to allow a police force to fire an officer who sold sexually explicit videos of himself and claimed to be protected by the First Amendment.