Andy, I’ll bite. Any of the grounds you mention–all squarely based in judicial philosophy–should be sufficient for voting against a nominee to the Supreme Court, or any other court. Jurists who would make up the Constitution as they go shouldn’t be given a pass just because they haven’t cheated on their taxes. Judicial philosophy is always a legitimate subject of debate, and a legitimate ground for senators’ votes, positive or negative.
The tougher question you ask is, can judicial philosophy ever justify a filibuster of a nominee? I wouldn’t want to answer yea or nay on that until another question is answered first–namely, what do we mean by “filibuster”?
Is it a “filibuster” any time one or more senators refuse to join a unanimous consent agreement (the customary means of controlling the terms and duration of debate in the Senate) that will, in their opinion, bring a nomination to a floor vote after insufficient debate? Such delaying tactics may be legitimately used if the alternative is that the majority leadership ramrods a nomination through the process, while a delay might provide some persuasive opportunity to the minority to change some minds in the hasty majority. If that’s a filibuster, I’m all for it under the right circumstances.
Or do we reserve the name “filibuster” nowadays for any occasion when 41 to 49 senators simply act to obstruct a floor vote permanently, with no intent to persuade anyone of anything, no matter how much time passes or how much talk occurs? That is the abuse of which Democrats have been guilty these last few years (and which I said here a week ago was the new principle of minority power implicitly enshrined in The Deal). If that’s a filibuster, I’m against it in all circumstances–certainly in cases of judicial or executive nominations, anyway, and maybe even in legislation too.
When a filibuster begins or is in progress, it may be hard to tell which of these is occurring, though with the passage of time it becomes pretty plain. The difference of principle is that the first encourages deliberation and facilitates the wise exercise of majority rule, while the second stifles deliberation and frustrates any exercise of majority rule. Clearly the Senate Democrats crossed the line from the first to the second when they made it clear that there were no circumstances under which they would tolerate a floor vote on certain judicial nominations.
This was the abuse that brought Republicans to the brink of stating that the rules required only a simple majority of the Senate to attain cloture on a judicial nomination. Would such a threshold make it impossible to engage in the first, less objectionable form of filibuster above? Probably not, since it would still remain possible to tie up the Senate for a decent interval just by objecting to a unanimous consent agreement to bring on a final vote. Cloture would still take time to achieve, would still usually result in ample debate afterward as it does now, and would not be achieved hastily in a Senate culture that still respects minority views and the individual senator’s right to be heard at length. (I never bought the “sky is falling” view of how the Byrd option would radically undermine that Senate culture.)
However, if senators in either party are to have a meaningful opportunity to change their colleagues’ minds about judicial nominees, another tradition must go–namely, the ridiculous practice of mincing around the questions any sensible person would ask the nominees during Judiciary Committee hearings. If you want to know what a nominee thinks of abortion, or the influence of international law, or anything of a substantive character, ask away–and expect real answers. We should tolerate nothing less than total candor on the subject of broad constitutional opinions and principles of reasoning, especially in hearings on Supreme Court nominees. Hiding behind “judicial independence,” or pretending that answering any real questions would invite improper speculation on cases that might come before the Court, just won’t do–not in an age when it cannot be assumed that nominees understand the difference between interpretation and policymaking. (An age that has lasted more than a century already, but that’s another story.)