WASHINGTON — At least once a term for 13 years, Justice Ruth Bader Ginsburg recalled, some lawyer arguing before the Supreme Court would mistake her for Justice Sandra Day O'Connor, or vice versa.
No matter that Brooklyn-born Ginsburg and O'Connor, raised on a ranch in Arizona, look and sound nothing alike.
The confusion arose because, even at the dawn of the 21st century, women on the court were "one- or two-at-a-time curiosities," Ginsburg said.
So she considered it progress that no one made that error after Sonia Sotomayor became a Supreme Court justice last year.
Now with Elena Kagan joining them on the bench for the start of the high court term in October, Ginsburg, 77, perceives an even bigger change. Kagan, 50, was sworn in Saturday by Chief Justice John Roberts.
"We are one-third of this court," Ginsburg said. No longer a momentous event, the appointment of a woman to the high court has become, Ginsburg said, "expectable."
"I don't think anybody's going to confuse Justice Kagan, Justice Ginsburg or Justice Sotomayor," she said.
But having three women on the court may not change the outcome of any cases. The justices, after all, regularly divide 5-4 along ideological lines in high-profile cases. Sotomayor's votes in her first year were very similar to Justice David Souter's, the man she replaced. Kagan is expected to vote much like Justice John Paul Stevens, who retired in June.
"Having this seat occupied by a woman does not in and of itself change the way this justice votes," said Vanderbilt University law professor Tracey George.
Academic studies have so far found just one area, sex discrimination lawsuits, in which the presence of a woman on a panel of federal appeals court judges appears to make a difference.
Ginsburg suggested that women were more likely to add a measure of civility to the court's work.
She is fond of her service with O'Connor, who retired in 2006. In disagreeing on some major issues, they showed that women "come in all sizes and shapes just like men do," Ginsburg said.