"McGrath: there is also the possibility that she IS guilty, right?"

Obviously, in principle it's possible that anyone might be guilty of anything. The principle is they are assumed to be innocent until and unless proved guilty.

And the other principle is that there are strict limits on what the state can be allowed to do. And that is a principle on which "conservatives" should be at least as hard to satisfy as "liberals" when it comes to accepting extensions of those elimits.