Well, if one of the idiots like Trump or Carson ended up being the nominee then sure. But that's not going to happen. If Hillary ends up having to debate someone like Kasich, she will fall flat. She can shine in a room full of Democrats easily enough, but I don't believe she has what it takes to impress in a non-scrimmage game.
That being said, you're counting your chickens before they hatch. Hillary might not be the nominee.
I have no fealty to Hillary. I just think she'd be better than all the alternatives.
I kind of liked Walker, but he didn't last. I'm keeping an open mind about Kasich and Rubio.
Frankly, I'm not seeing where Kasich is that polished of a debater. Sounding 'not crazy' in a room full of crazy people isn't much of an accomplishment. Hillary has gone toe to toe with Obama and Biden, who are quite good debaters.