You are mistaken. Miers has spent most of her life in political contexts - ABA head, city council, helping Bush in the WHite House, Texas gambling commission.
As such, she is *more* susceptible to beltway pressures and influences than a cloistered Judge.
Are you familiar with her history? In each of those capacities, she largely went against the grain--proposing, for instance, that the ABA drop its blanket pro-choice support.
I'd say she is LESS susceptible to pressure, especially if she survives this beltway attempt to derail her nomination.
Where do we keep our "cloistered" judges? (Not that it's a bad idea! LOL!) Mark Levin has attributed leftward drift where it occurs to judges who are drawn to the DC social scene.