I think he knew but Trump pretty much boxed him in. There was no way he could drop out of the debate and not look like he was following Trump. And then he compounded his error by basically saying Trump was too chicken to debate. He would have picked up a lot more votes if he had simply said "You know what, I have to give credit where credit is due. Donald is right to skip this. These debates are nothing but an opportunity for the left to try and take out anyone who is not a moderate or liberal member of the establishment. I'm going to go. I don't expect I'll get fair treatment. I expect I'll be beat up. But the thing to take away from this is that the process is broken. "
That would have been a classy and awesome response...hat tip to you.