I've seen a lot of silly theories put forth by liberal bloggers and commentators about why the "conservative elite" opposes the Miers nomination. So let's put the shoe on the other foot.
How would the "liberal elite" have reacted if, instead of nominating Ginsburg or Breyer, Clinton, after promising to nominate Justices in the mode of Thurgood Marshall and William Brennan, had nominated a managing partner in the (Little Rock-based) Rose Law firm who had donated to George Bush's 1980 presidential campaign (as Miers donated to Al Gore's 1988 campaign); was Clinton's personal lawyer; was a big muckety-much in the pro-free market Chamber of Commerce (analogous to Miers and the ABA); had publicly opposed affirmative action (as Miers has publicly supported it); had denounced the ACLU(as Miers has more or less denounced the Federalist Society); whose supporters could come up with no better rationale for her appointment than that she was a female Unitarian who had privately expressed the view that abortion should be legal; and who otherwise had analogous credentials and background to Ms. Miers, except with the opposite ideological tinge?
My hypothesis is that such a nominee would have run into at least as much opposition from liberals as Miers has faced from conservatives, and that even fewer liberals would have bought Clinton's "trust me" line than conservatives have bought this line from Bush.