Supreme Court Justice Sandra Day O’Connor’s retirement has liberal groups in a tizzy about her Bush-appointed replacement. O’Connor, described as a “moderate conservative," provided an important swing vote which, it seems, may be lost in the new court.

O’Connor was the first woman to serve on the Supreme Court, and her retirement seems to strike a chord particularly with women (see this and this).  While many point to Attorney General Alberto Gonzales as a likely choice (a good discussion of this here), many are already advocating a female replacement.

This is especially true because O’Connor represents a much-needed reproductive choice-friendly candidate. This TPM Café post names abortion as the crucial political question in the process. Media Girl provides the text of the Roe v. Wade follow-up Planned Parenthood v. Casey, which O’Connor supported, and the Supreme Court Nomination blog has useful legal coverage on the abortion issue as well. Feministing is already raring for a fight on this front, as are NARAL, Planned Parenthood, the ACLU, and MoveOn.

Will a battle, symptomatic of the new polarization, enter the floor of the Senate? Read Godfrey Hodgson for an analysis of the recent filibuster deal, which could fall through in the process. The Judiciary Committee’s Chairman, Arlen Specter (R-Pa.), who will chair the appointment hearings, has been quoted as saying he does not expect a filibuster and others have followed suit. Daily Kos’ response to this piece, which argues the filibuster deal will prevent liberal dissent when it comes to the nomination: “an appointment to the SCOTUS is DIFFERENT. Extraordinary, if you will.” Seems we may be in for a brawl.

Many observers call these claims alarmist; even if a very conservative candidate does go through, Volokh argues that the new appointment may not have the impact liberals predict and a New York Times piece demonstrates that historically, appointments haven’t always done what their appointers desired.

These arguments are reassuring, and we want to believe them; isn’t the US government about checks and balances after all? It seems that, at root, we counted on O’Connor to stem the tide of conservative decisions - time will tell whether this function can be otherwise served, by the new justice or by the system itself.