He's been in the media for 40 years without anyone calling him racist and he's been around supermodels without anyone calling him a sexual predator or anything like that. But all of a sudden they find he is all of that and even worse.
And on the other hand, how much negative stuff is reported about Hillary? There certainly is lots of material with all that WikiLeaks has put out. Almost zero, she is instead praised like a Soviet leader. She's a wonderful human being and politician that somehow made $250 million while in office.
Furthermore, plenty has been said about Hillary. The Wikileaks leak was on the front page of the NYTimes, WaPo, and tons of other newspapers. So were the allegations about her health in September. Unfortunately for Trump, none of these attacks have stuck with voters.
But "voters" haven't had a voice since the primaries...only the media has. "none...stuck with the voters" = not covered by the media.