Is the job of a moderator for 2016 US presidential election debate very difficult?

Is it possible that Holter might have been easier on Clinton “Holter faces criticism”: http://www.foxnews.com/politics/2016/09/27/holt-faces-criticism-over-how-moderated-first-presidential-debate.html

“Wall Street Journal.com Holt faces tough test”:“http://www.wsj.com/articles/debate-moderator-lester-holt-faces-tough-test-1474927188
because Trump got a ton of free publicity (that Hilary Clinton didn’t) on a daily basis? As well could it be that because of the free ride lame questions by Matt Lauer, Chuck Tood, and others including the comedian Jimmy Fallen?