Attacking the media is not healthy or helpful.
His most egregious crime is destabilizing public trust in climate change facts. The world climate is changing because of human actions, and drastic action must be taken by world leaders to prevent catastrophic damage (aka, human extinction events). Leaders like Trump that deny the facts contribute to the damage that may cause these extinction events.
So if you call contributing to effects that could lead to flooding most of our major population centers with rising sea water over the next hundred years "making america great," by all means support the man.
EDIT: Because Trump supporters always say "but Trump didn't say x y z!"
Let's listen to the man: https://twitter.com/realDonaldTrump/status/26589529219124838...
"Listen to what he says, he's going to make america great." Yea, I'm listening.