We might distinguish between two grounds for evaluating Supreme Court nominees. The first is technocratic. Is the nominee excellent? Does the nominee have relevant knowledge and experience? The second ground is political. How is the nominee likely to vote? How does the nominee approach the Constitution? (The word "political" is too crude, because no nominee is likely to approach the law in simple political terms; but let's put that issue to one side.)
On technocratic grounds, the following recent nominees were obviously outstanding: Roberts, Breyer, Ginsburg, Scalia, and Bork. (Douglas Ginsburg belongs in that category as well.) No one could doubt the ability and relevant experience of these nominees. Their records clearly demonstrated that they were first-rate. The same could be said of several other recent nominees as well.
On political grounds, Judge Bork was of course found unacceptable by a majority in the Senate, and Republican leaders made it clear to President Clinton that they would reject some people on his list; they also indicated that Breyer and Ginsburg were sufficiently moderate. (Let's put to one side the intense debates about whether Breyer and Ginsburg are in fact moderate; at least it can be said that they do not share the liberal views of William Brennan and Thurgood Marshall.) For their part, many Democrats concluded that Chief Justice Roberts was well within the acceptable range.
What about Harriet Miers? She might be superb, but her record and experience certainly do not compare to those of recent nominees. She has neither been a judge nor had much experience with the Supreme Court itself. There's nothing comparable to the appellate work of Chief Justice Roberts, or the judicial and academic work of Breyer, Ginsburg, Scalia, and Bork. Even Souter and O'Connor, with their thinner records, had judicial opinions to evaluate.
On political grounds, there are at least equivalent questions. We appear not to have any sense of her general approach to constitutional law. From the public record, it was possible to give at least a rough and general evaluation of all or almost all of the recent nominees. Apparently that's not true here.
A reasonable conclusion is that this nomination should be viewed with uncertainty and puzzlement. A silver lining: The uncertainty and puzzlement should not divide people along political lines.