The implication is pretty clear.
She's talking like a politician.
If she didn't mean to make the charge, she wouldn't have brought up the possibility.
Would someone have reason to be offended if I said "It's possible that he beats his wife?"
Are you saying that "absolutely, positively everyone who has criticized Miers is NOT sexist"? I know several people who are. I don't care if the nominee is a man or a woman, I just want someone I know I can trust! But there HAVE been some sexist comments.