The issue is not the venue of Miers's constitutional scholarship, experience and engagement. The issue is their nonexistence...
Constitutional jurisprudence is... by definition, an exercise of intellect steeped in scholarship. Otherwise it is nothing but raw politics. And is it not the conservative complaint that liberals have abused the courts by having them exercise raw super-legislative power, the most egregious example of which is the court's most intellectually bankrupt ruling, Roe v. Wade ?
Although the Constitution is a plain document, the meanings behind many of its words are heavy with historical meaning. Take "establishment of religion," as an example. Many people today, because of the cultural weight assigned to that phrase by the Supreme Court, think that "establishment of religion" means that the government cannot display a Christmas Tree at all or without appropriate "secular" balancing displays (such as a plastic reindeer or frosty the snowman). People think this, of course, because the Supreme Court said as much in Lynch v. Donnelly and Allegheny County v. ACLU. In those two cases, the Court held that the display of religious symbols by the government would only be permissible if the context is clear that government does not "favor" religion. Thus was born the "plastic reindeer rule."
The last time I checked, I don't think the Constitution mentions plastic reindeers. But it does mention "establishment of religion," which is a very specific thing and of which the Framers had intimate knowledge. England had an established religion: the King was the head of the Anglican Church. In England, there were vicious laws against practicing Catholicism or any other unapproved form of Christianity. This is the reason the Pilgrims left for the new world, to be free from government persecution. Notably, however, the New England colonies didn't shirk from establishing their own government-selected religions. The idea at the time was that if you had a different religious belief, you would move to a different area of the country (Rhode Island accepted nearly anyone as they were fiercely independent, and Maryland was originally for Catholics). The Framers did not want the newly created Federal Government to wipe out those established religions in the various states, which is why the First Amendment says that Congress shall make no law respecting the establishment of religion. States at the time were free to continue operating their established religions, and did so long well into the 1820s.
It is this kind of historical perspective in understanding a phrase of the Constitution that originalist jurisprudence demands. Does Miers posess any of that? Who can say? Given the important of avoiding another Souter (an outright flip to the left) or a Kennedy, O'Connor, or Blackmun (gradual but consistent shift to the left), we cannot gamble with this nomination. But the President and Miers' supporters ARE asking us to gamble. So should we come out and demand her nomination be withdrawn, or urge her defeat? Powerline says no. Professor Bainbridge hasn't said anything definitive yet. Captain Ed says he bases his support on Miers only to avoid a destructive party schism. And of course, Hugh Hewitt thinks that we're all a bunch of idiots for even suggesting the possibility of defeating her (or something like that).
Of course there's always the possibility that Miers will be the next Scalia. But I wouldn't bet on it. Right now, I hope she withdraws herself after a poor performance before the Judiciary Committee. The Democrats are going to vote in favor of her unless they get spooked by her pro-life opinions. But barring that, the Democrats know that she is malleable given her lack of any jurisprudential philosophy, and that is probably the best they can hope for. If Republicans are forced to vote in the Senate on her nomination, I think they will probably vote to confirm. The only chance at defeat is before the Committee hearings, or during them. Which is why people are making noise now, because as the clock ticks, it becomes too late. At this point in time, by continuing to criticize her without saying what we'd want, it's almost an implicit argument for her defeat (which is why Hugh Hewitt was so upset over the uproar to begin with).
Very soon, I think those who want Miers to be confirmed, for whatever reason (like to avoid a split in the Republican party - a split which is just as likely if she IS confirmed), will soon drop the issue. Those who want Miers defeated will continue to criticize her, and force her defenders to respond. Whether this affects any of the Republican Senators is another matter entirely.