I’m fuzzy on Harriet Miers other than I know Frum opposed her over some personal spat. I thought it was an odd selection but don’t recall what she was notorious for.
Harriet Miers was notorious for not having the experience or the conservative bona fides for being a good, reliably conservative SCOTUS pick. It was Bush picking one his loyal underlings, a dangerous way to pick SCOTUS nominees.
It created a breach of trust in conservatives towards bush that increased willingness to critique him.