No, it hasn't, and if it had, the Right wouldn't keep spinning findings of a predominance of Democratic Party membership among media employees as if it were the same thing as a finding of leftward bias.
This was a 2 minute search of Google Scholar:
^1 "...the mainstream press in America operate within a narrow range of liberal beliefs... only a narrow band of liberal thought is supported by the press"
^2 "Our results show a strong liberal bias"
[1] https://www.researchgate.net/profile/Jim_Kuypers/publication...
[2] https://academic.oup.com/qje/article-abstract/120/4/1191/192...
Unfortunately, there is no more compromise in today's world. People just want to win because even giving up even a small amount of ground to an opponent is considered a complete failure.
This, of course, begs the question: how do you fix it? I don't know.