I recall reading some years ago an in-depth expose about McCain and his questionable friends/dealings in AZ. I think there is likely plenty there to dredge up. McCain may not be McClean.
Just look at the way Hillary looks at McCain, when she can spare a second from savaging Obama, and licks her chops.
No, she was never afraid of Rudy Giuliani or John McCain, either one.
Don't think she was afraid of Fred Thompson, either, but for a different reason: she and Slick had tangled with Fred once before, using their intermediaries (Jamie Gorelick and Richard Ben Veniste), and won. Or at least they kept Fred from getting to the bottom of Chinagate and Slick's sale of his office to the Chinese.