There is little legal history to show how Sotomayor would rule in an abortion case, but the fact that her stance is unknown has caused some concern among abortion rights groups that President Obama's nominee can't be counted on to uphold the 1972 Roe v. Wade decision on abortion. Those concerns stem from decisions she has made in cases that were about the First Amendment, free speech and civil rights, but involved abortion in some way.
In 2002, Sotomayor sided with the Bush administration in a case brought to court by the Center for Reproductive Rights, which challenged the ban on government funding to international groups that provided abortion or abortion-related services, also known as "Mexico City Policy."
"We were very disappointed when the decision came out. We thought we had good constitutional claims," Nancy Northup, president of the advocacy organization, the Center for Reproductive Rights, told ABCNews.com. "Judge Sotomayor and the panel believed the precedent that our claims couldn't go forward."
"Because this classification 'neither proceeds along suspect lines nor infringes fundamental constitutional rights,' it must 'be upheld against equal protection challenge if there is any reasonable state of facts that could provide a rational basis for the classification,'" Sotomayor wrote about her decision.
In another 2004 civil rights ruling, Sotomayor ruled on the side of anti-abortion protestors who sued police officers for brutality outside an abortion clinic. And in a 2006 immigration case, she ruled to grant a Chinese woman extended amnesty on the basis that she faced forced birth control in her home country.
Those decisions have some on the left saying her views need to be made public in confirmation hearings.
"Because we don't know where she stands on the constitutional right to abortion, we think it's important that during confirmation hearings, that senators explore her view... and that she expresses her legal views on the matter," Northup said.
NARAL Pro-Choice America's President Nancy Keenan echoed similar words in a written statement.
"Discussion about Roe v. Wade will -- and must -- be part of this nomination process," Keenan said in an advocacy message sent to supporters.
Asked if Obama knows for a fact that Sotomayor supports the ruling in Roe v. Wade, White House press secretary Robert Gibbs said that the president does not have a litmus test on abortion.
He said Wednesday that Sotomayor and Obama did not talk about abortion or Roe v. Wade in their meeting last week, but he suggested that the two were in agreement on their views in general, adding that the president and Sotomayor talked about her views on "unenumerated rights in the Constitution and the theory of settled law."
"I know he feels comfortable, generally, with her interpretation of the Constitution being similar to that of his," Gibbs said. "He feels comfortable with where she is."
Legal experts say it is too soon to tell how she may vote on a case that resurrects the Roe v. Wade discussion.