It has been suggested that in the debate against McCain, Obama had the press in his pocket. They fired pre-authorized questions for which Obama had prepared answers. McCain wasn't privvy to the questions/answers ahead of time. Totally rigged. That didn't happen in the Romney encounter. The game wasn't rigged and Obama demonstrated his lack of ability.
Say what you will about Jim Lehrer, he is a professional. A couple of time there, he couldn’t help himself deferring to a sitting liberal President, but for the most part he tried to be fair.
I would be happy with him moderating all three debates. I also thought that Gwen Ifill did a decent job in the 2008 VP debate. That might have been because she was the tiniest bit excited about a female candidate. Tom Brokaw and Bob Schieffer were terrible. Schieffer will again be moderating the final debate this year, and I have no idea why the Republicans keep agreeing to him. Perhaps he has seniority or some such nonsense.