If not for Sandra Day O'Connor, Anthony Kennedy, and David Souter, then the base might be willing to just take on faith the assurances of the latest Republican President's latest SCOTUS nominee. But because of those three mistakes, the days of blind faith are over.
In the end, Miers sunk herself by making it almost impossible to base her alleged conservative judicial philosophy on anything more than Bush's word. Her recently unveiled speeches where she seemed to justify judicial activism as necessary when the legislature doesn't do the right thing (with 'right' always being defined as something the people would reject if given a choice), and where she used the left's characterization of the pro-life position were the final nails in the coffin.
Ding! Ding! Ding! We have a winner!