I will go with the named source, thank you very much.
With respect, it's not a matter of a named source denying it.
The article names Sara Taylor, director of the Office of White House Political Affairs, as one of the people making the calls. Yes, she denies it, but given the very sensitive nature of such an operation, if it is in fact going on, it's altogether predictable that she would.
Of course I don't know whether the story is accurate or not. But surely, with the firestorm of criticism of the Miers appointment from some of the most respected conservative voices, you wouldn't be surprised if the WH is considering a Plan B, would you?