And "good cause" was spelled out by the Dem members, as I noted - and would allow filibustering over preceived extremism. To the Dems, any professed originalist is an extremist. Rogers had to couch his words very carefully to get around that. Miers doesn't have a judicial history for the Dems to attack her with.
If the Dems want to be seen to obstruct the nomination of someone like JRB, then I think that's a fight worth undertaking. Frankly, the political consequences are likely to benefit the GOP no matter what the outcome. At worst, Brown is not confirmed and the GOP base is energized for 2006. At best, she's confirmed and we have a certain conservative vote on the bench for the next few decades.
What's the downside?