Three reasons...

[DawnneOBTS]

that the Shrub could have possibly nominated Harriet Miers:
1. If you are a crook or bunch of crooks like BushCo, you need a good lawyer, I would think. Maybe she is a good lawyer, who charges mega $$$. Imagine the legal defense this administration needs, because what haven't they done? Now, how much money owed are we talking, here? Maybe more than BushCo wants to pay, perhaps?
2. Really good sex/blow jobs. Harriet Miers is single, never married, no children. How many people did she "do" to get the role of "Harriet does Dallas?" So, a lot of favors are owed to her, perhaps.
3. Simple, outright blackmail. Hey, capitalize on this bunch of losers while you can, Harriet. You have so much dirt on them you could bury them, I'm sure, so they have to do what you want, whatever you want, and you really want this job.