“I really don’t understand the widespread assumption on the Right that she is so totally ruthless that she could pretend to support BO for all she’s worth, but at the same time be stabbing him in the back.”

Well, if you’re going to stab someone in the back, that’s how you do it. If you come at him with knife raised yelling “I’M GONNA STAB YOU IN THE BACK SUCKA!” he doesn’t turn his back on you.

Instruments of darkness tell us truths
Win us with honest trifles
To betray us in deepest consequence.