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." In another 2004 civil rights ruling, she 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.
The White House has been mum on the subject, except to defend Sotomayor and to say that her views are aligned with those of President Obama.
"I know he feels comfortable, generally, with her interpretation of the Constitution being similar to that of his," White House Press Secretary Robert Gibbs said. "He feels comfortable with where she is."
Anti-abortion groups have also expressed concern on the basis that Obama's pick is likely to side with the president himself in a case involving the Roe v. Wade decision and because of her limited history on these few cases.
"President Obama has said when he was campaigning, repeatedly, he would only nominate a justice to the Supreme Court who supports or affirms Roe v. Wade. President Obama has not backed off that statement," Mahoney said. "You have to operate under the assumption that she's pro-choice, that she affirms Roe because of what the president said."
Tiller's murder caused a widespread firestorm of reaction, with both sides condemning it, except for a few people such as Randall Terry, founder of anti-abortion group Operation Rescue, who said in a statement: "George Tiller was a mass-murderer. We grieve for him that he did not have time to properly prepare his soul to face God. I am more concerned that the Obama administration will use Tiller's killing to intimidate pro-lifers into surrendering our most effective rhetoric and actions. Abortion is still murder. And we still must call abortion by its proper name; murder."
Terry said in a press conference Monday that his organization will protest outside the Capitol during the confirmation hearings.
"It is my conviction that every pro-life senator on that Hill needs to insist that she come clean on where she stands on child killing," Terry said. "And if she won't overturn Roe, then she has to be filibustered."
The president issued a statement saying he was "shocked" and "outraged" by the murder. "However profound our differences as Americans over difficult issues such as abortion, they cannot be resolved by heinous acts of violence," Obama said.
As Sotomayor prepares for her Senate meetings, it remains to be seen what impact, if any, Tiller's murder would have on the abortion debate on the Hill. For now, both groups remain uncertain as the confirmation process begins.
ABC News' Arlette Saenz contributed to this report.