I am arguing that once they picked up that battle, they should have continued it, even though if they would have lost at the end. They knew what risks there were ahead of the game (the number of Senate seats has not changed!) so they should have been prepared to take these risk or stay out of the fray. I think that picking up that battle and sustaining defeat would be a better strategy than capitulating, because it would hand the Repug a Pyrrhic victory instead of a real one. If the fuckers took the "nucular option" and changed the filibuster rules, it would come back and bite them in the ass very soon, as it is them who usually use it. Not to mention the public outcry, since, as you said it yourself, the public was with the Democrats on this issue.
You may argue that Democrats were good sports and did not want to wreck this "venerable" (if not obsolete) institution, but if so, they should have not picked up that battle in the first place (they knew they would not prevail if it went nucular). But once they started, they should go ahead and fight, provoke the "nucular attack" and bring down that fucking "venerable" institution down with them. It would better serve them in the long term, if they manage to emerge from their current nadir.
And this whole "moderate" and "conservative" distinction is really rearranging seats on the deck of the Titanic. It may matter in a parliamentary system, not under the Ein Reich Ein Partei system that the US has.
Wojtek