The news media is heavily biased to the far left. This is due to the bias of ownership, as well as the low salary cost of young reporters who tend to lean left.
One of the causes of the bias is that decision-makers in the media organizations preferentially hired those that shared their ideological commitment. This is easier in fields where a worker cannot prevent his or her ideological commitment (or lack thereof) from showing in his or her work product. Besides journalism, other fields with this property are the social-science and humanities departments of universities, which is why those fields were captured by Leftist many decades ago whereas other fields were captured only much more recently.
One department of the social sciences has resisted capture by Leftists, at least in the US, at least the last time I looked, namely economics. One could argue that that is because it was captured first by liberal or libertarian ideologues.
This comment is restricted to the US and Britain because those are the only 2 societies I know well enough for my observations to have any value. Also, the OP is about American teenagers specifically.
If you look at media in the US, they will actually bend over backwards to explain away what Trump is saying or doing. They will present "both sides" on equal footing when one side is legitimately insane. And, when they refer to his speeches and policy, they actually make it sounds much MORE reasonable than it is.
Like, when they play clips of trump speeches, they always leave out the 30+ minutes of rambling. And when Trump says something obviously racist, they, I'm sure in an effort to give the benefit of the doubt, explain it in a way that is not racist. Oh, maybe he said that they're eating the dogs and cats because he's misinformed...
The problem is normal people get only neutral benefits from the benefit of the doubt. But bad actors can, and do, abuse the benefit of the doubt and get much more out of it.
It's so bad that even when Trump does something fucking stupid and doesn't offer any coherent explanation, the media will actually make up potential explanations FOR him and talk about those. They're so biased in his favor he doesn't even need to make arguments any more - they will make arguments for him that are reasonable sounding.
And, keep in mind, I'm not referring to Fox here. This is CNN and MSNBC.
Seriously, go listen to what they say trump said or did and then listen or read what Trump ACTUALLY did. It's always much, much worse.