Well, some have actually, but Condi has dated. In fact, she was engaged a long time ago.
I have absolutely no interest in Condi's sex life. But the fact that she once had a serious relationship with a man doesn't mean she's not a lesbian. I have had personal experience with at least one married woman who divorced her husband and switched teams. And then there's the ECUSA bishop Gene Robinson, who was married with two kids and then got a divorce and is now living with a male lover.