Justice Sandra Day O’Connor announced her retirement from the Supreme Court, pending the appointment of her replacement.

So it’s time now for the battle to begin in earnest. Many people have been expecting the retirement of Chief Justice Rehnquist; O’Connor was considered more of a longshot. But by retiring before Rehnquist, O’Connor has complicated the replacement battle.

It will be particularly interesting because liberals see O’Connor as a conservative; conservatives often see O’Connor as a moderate liberal. So in “balance of the court” calculations (as though that balance must be maintained or is sacred), liberals count her on the conservative side. So the Republicans have a chance to replace an unreliable voice for Constitutional restraint with a serious jurist in the vein of Clarence Thomas or Antonin Scalia, all while being able to tweak the liberal opposition that it’s merely swapping one conservative for another, and thus shouldn’t upset the “balance” of the court.

But they won’t; congressional Republicans have demonstrated an appalling lack of spine (or reproductive organs) in confirmation fights already. I have serious doubts about Frist’s ability to keep the troops in line, or even his taste for the fight. And what I fear is that we’ll trade O’Connor’s occasional “conservative” votes for another David Souter: a liberal snake in weasel’s clothing.

A complicating factor is the 2006 election, and the posturing it inevitably engenders. Again, this should work in the favor of the Bush administration, as liberals will be forced to more explicitly defend their religious faith in the abortion-on-any-whim in the judicial confirmation conflict, but have to be more restrained about it in election campaigns. But again, I doubt that the Republican leadership will focus attention on this critical point as it should.

I suspect that we will hear the first call for “reason” and “bi-partisanship” from the Democrats before the day is out. And we will likewise hear the first shrieks of outrage from the other side of the Democrats’ mouths before the weekend is over. Should make for an interesting summer.