I have paid attention to news media since the 60s. I perceived a shift with the anti-war sentiment triggered by Viet nam (war?). In fact the evening news influenced public sentiment against participation in Viet Nam with unpleasant (negative) coverage. Since I was drafted back then (1970) I was opposed to Viet Nam too (duh).
While I delivered newspapers as a paperboy in the 50s I did not pay close attention to the news therein. I hope you aren't shocked if I shared that millions of people have exactly the opposite opinion from you. I wouldn't get news from either but they both clearly cater to provide what their different leaning audiences prefer to hear (its just bidness).
For personal amusement I tuned into MSNBC the night that President Trump was elected to watch them all melt down on screen. HUH... It looks like fact checking preferentially checks POTUS statements. Some liberal newspapers are quite aggressive.
Fox has on air talent, some characterized as news readers, some news anchors, and some as political commentators. MSNBC calls them all "news" correspondents (cough). I've heard some partisan rants from those "news correspondents" that make some of my friends here sound apolitical.
I guess the appearance of bias is all relative to our own personal bias... (I am right leaning-libertarian-conservative, and according to some here a sloppy thinker :
).
JR