The death of Arlen Specter inspired a predictably conflicted reaction from supporters of abortion rights: He was the guy who kept Robert Bork off the Supreme Court, perhaps in the process saving Roe vs. Wade -- Specter's favorite "super-duper precedent." But he also was the pitiless inquisitor of Anita Hill and may thus have been instrumental in the confirmation of Justice Clarence Thomas -- and Thomas is no friend of Roe. (In 2007, Thomas wrote that "the court's abortion jurisprudence ... has no basis in the Constitution."
The cynical view, of course, is that while Specter genuinely supported abortion rights, he was first and foremost a supporter of Arlen Specter. After alienating conservatives with his vote against Bork (with whom he differed on more than abortion; he also pounced on Bork's 1st Amendment views), Specter, according to this view, tried to win back some of them by supporting Thomas. (Thomas was confirmed in 1991; Specter was up for renomination and reelection in 1992.)
That wasn't Specter's last recalibration. After the 2004 election, Specter injudiciously announced that the Senate would not confirm any Supreme Court nominee who would overturn Roe. Oops. Conservatives mobilized to deny Specter the chairmanship of the Judiciary Committee, which handles judicial nominations. Specter salvaged his chairmanship by indicating that he would likely support George W. Bush's nominees and wouldn't impose an abortion litmus test.