In a country where nearly 1.2 million people are practicing lawyers, more than 45 percent of law firm associates — and 18 percent of partners — are women. Nearly a fifth of the nation’s law school deans are women, as were nearly 48 percent of the most recent class of law school graduates.  And that is to say nothing of other high-level positions, like governorships, if Mr. Obama chooses to go outside the appellate courts to pick a political heavyweight who brings coalition-building skills as well as legal acumen.  In 1981, just one governor was a woman. Today there are seven — not counting Janet Napolitano of Arizona and Kathleen Sebelius of Kansas, who recently resigned their governorships to join Mr. Obama’s cabinet.  Ms. Napolitano, who is also a former United States attorney, is thought to be a candidate for the court in some circles, as is Gov. Jennifer M. Granholm of Michigan.  Yet despite the rising prominence of women in the legal profession and the political world, the Supreme Court remains something of a male-dominated throwback. Since Justice O’Connor retired in 2006 and was succeeded by Justice Samuel A. Alito Jr., the only woman on the nine-member court has been Justice Ginsburg, who is 76 and recently underwent surgery for pancreatic cancer.  That imbalance — and the possibility that Justice Ginsburg will be next to leave the court — is one reason some are calling for Mr. Obama to appoint a second woman to the court.  “We think it’s incredibly timely and important that the president replace Justice Souter with a woman, and hopefully more women to come, so that the court will be representative of women in the profession,” said Roberta Liebenberg, a Philadelphia antitrust lawyer who heads the Commission on Women in the Profession at the bar association.  Near the top of many lists of women as possible nominees is Sonia Sotomayor, 54, a federal appeals court judge of Puerto Rican descent. A Yale Law School graduate, she was appointed to the district court by the first President George Bush and elevated to the appeals court by Mr. Clinton.  Other potential candidates among the nation’s appeals courts judges include Kim Wardlaw, 54, and Diane Wood, 58, who was a colleague of Mr. Obama’s when he taught at the University of Chicago Law School.  Two former law school deans, Elena Kagan of Harvard and Kathleen Sullivan of Stanford, are also widely considered to be potential nominees. Ms. Kagan, 49, was an associate White House counsel in the Clinton administration and recently became solicitor general; Ms. Sullivan, 53, is a constitutional law professor.  Curt Levey, the executive director of the Committee for Justice, a conservative legal group, said conservatives were convinced that Mr. Obama would pick a woman to replace Justice Souter and were focusing opposition research efforts on 17 women, whom they have divided into two tiers based on their perceived chances.  “The men are in a separate category,” Mr. Levey said.  It was once rare for women to become lawyers, but they began attending law school in much greater numbers four decades ago because of factors like the Vietnam War and the rise of the women’s movement, Ms. Rhode said.  In 1964, A.B.A. statistics show that just 4 percent of law students were women. By 1974, the figure had quadrupled, and it had more than doubled again a decade later. Today, just under half of all law students are women.  At the same time, presidents, beginning with Jimmy Carter, began appointing significant numbers of women to federal appeals courts, which has been the primary source of Supreme Court nominees in recent years.  According to data compiled by Russell Wheeler of the Brookings Institution, in 1981, when Reagan plucked Justice O’Connor from a state court, there were just 11 women among federal appeals court judges. In 1993, when Mr. Clinton picked Justice Ginsburg, she was one of just 23 such judges. But today, there are 47 women on the federal appellate bench.  To be sure, that does not mean that Mr. Obama has 47 realistic options among the women on the appeals courts. Republicans appointed 25 of them, Mr. Wheeler’s data shows, while three-fourths of the Democratic appointees are over 60, meaning they would probably have a less enduring impact than a younger appointee.  Still, Nan Aron, president of the Alliance for Justice, a liberal legal group, said the growth in the pool of women on the appeals courts and in the broader legal world would put pressure on Mr. Obama to pick one.  “There are so many more women in the legal profession and on the bench throughout the country, and it’s imperative to have greater gender representation on all of our courts, including the Supreme Court,” she said.  A version of this article appears in print on , on Page A1 of the New York edition with the headline: Wider World of Choices to Fill Souter’s Vacancy: Opportunities Rising for Women. Order Reprints| Today's Paper|Subscribe
Many expect President Obama to choose a woman to replace Justice David H. Souter — and he has a lot of choices.