At first blush, it seems difficult to understand why the nuclear option is being pushed forward so resolutely. W's record of judicial confirmations is far higher than Clinton's was even though his appointment record is far more partisan. There's every reason for W to expect his record to be even better in his second term. He may owe Priscilla Owen a favor or 2, but it doesn't seem to be worth risking shutting down the Senate over her nomination.
The stakes of this battle, are in fact, much higher, as the Rethugs, as usual, are managing several innings ahead. They aren't risking a Senate shutdown over a few circuit court nominations. They're risking it over several nominations to the Supremes.
Rehnquist obviously will retire at the end of this term, and O'Connor is probably not far behind. Stevens will probably not last until 2009. Ginsburg is a cancer survivor. Kennedy isn't getting any younger. Odds are that W will get to fill at least 2 and maybe as many as 4 seats, thereby defining the course of the Court for a couple of decades.
Once Rehnquist retires, there's an excellent chance that W will try to elevate either Scalia or Thomas to CJ. While Scalia appears to be the more likely candidate given his visibly superior intellect and his critical role in Bush v. Gore, I wouldn't rule out a Thomas nomination. He's much younger, and W might like to be able to trot out the first black CJ to show his alleged openness on civil rights.
A Scalia nomination would be a dogfight, and a Thomas nomination would be all out war. Thomas barely snuck in in 1991, and he'd probably face an even tougher fight this time. Scalia might not survive a Dem filibuster, and Thomas would never stand a prayer of surviving one.
Like so many fights that the Dems have generally lost against the R's, this one has little to do w/ the terms over which it is being publicly waged. It has everything to do w/ longer-term goals which are not being publicly debated at present. The Ben Nelsons who are apparently trying to negotiate a short-term compromise, accordingly, are missing the longer term implications involved.