It's like figure skating or diving. Since there is no objective scoring people are going to say their guy won. Unless their guy was a total loser. Then they will blame the moderator.
According to a body language expert Trump won followed by Christie and Walker. The others all looked like wimps Nonverbally (through his body language) Donald Trump won Thursday’s Republican presidential debate,” body language and nonverbal communication expert David Givens writes in the Guardian. “His hand gestures, facial expressions, and tone of voice dominated, and made the competitors seem ineffective, even wimpish.” Continues Givens, “In all the candidates save Trump, hand gestures — which accent words and show emotional conviction — were weak, ephemeral and often hidden from view along the body’s sides or behind the podium. Trump’s gestures, in contrast, were strong, extended, forceful, and open to view, which is to say, very visible. In short, he convinced via nonverbal actions, while his competitors seemed weak — wimpish, again — by comparison. On TV, Donald’s big gestures, big hair, big hands, big jaw, big face and pugnacious lip pout clearly trumped the other candidates’ smaller hand gestures, boring, close-cropped hair, smaller hands, weaker faces and jaws, and unexpressive facial expressions.” https://www.yahoo.com/health/who-won-the-gop-presidential-debate-when-it-126104902167.html