[republicofdavis]

"Why after the Roberts selection was it then manditory to pick a female to replace a female?"

I don't know. Political considerations? If so, there were many more qualified female nominees.

[Do not dub me shapka broham]

There were more highly qualified female litigators.

I'd venture to guess that if he searched long enough the president could probably have found a few female contract attorneys that were better qualified for this seat as well.