Well, that and the fact that nobody in his party actually liked him. I liked the clips of Mitt I saw from that first debate. In fact, it's why I tuned in for the third debate, but that Mitt was nowhere to be seen. The guy should have went all in during debates two and three, but he didn't, and here we are.
I think he shot his load during the first debate and had to sit around the set as impotently as Flopsy Kn0% for the other two.
But, you're right. The Multiple-Mitt mess definitely cost him. Hell, it's why the Salt Lake Tribune refused to endorse him and they're the largest Mormon paper in the world.