I think the newspaper endorsements line was meant to
be evidence, but I'll flesh it out a little.
Of the 100 largest-circulation newspapers in the US, 57 endorsed Clinton while only 2 endorsed Trump. Of the top 50 papers, two gave no endorsement, two endorsed "not Trump", and one endorsed Johnson. The other 45 directly endorsed Clinton, with zero endorsing Trump. So: when traditional journalists and editors at major newspapers took explicit positions on the election, they almost all opposed Trump.
This is obviously a different question than "is the media conservative or liberal?", "is the non-editorial coverage at major news organizations generally anti-Trump?", or "are news organizations employing a partisan agenda in their decisions about how to cover Trump?
The first one of those questions is relatively easy to answer: according to an Indiana University survey of 1080 journalists in broadly 'traditional' roles, 7% identify as Republicans, compared to 28% who identify as Democrats. The number identifying as Republicans has also been falling faster than the number identifying as Democrats in equivalent prior surveys.
The second one is more open ended, but I think we can at least sketch the outlines of an answer.
Intuitively, I would propose that cable television leans left with one obvious exception, while local news and television stations are much more scattered - and less dependent on the views of their journalists, since they often have purchased content and partisan owners like Sinclair.
Factually, the Shorenstein Center at Harvard finds that in the first 100 days of the Trump administration, news coverage of Trump was 80% negative. They find that CNN and NBC were most negative, while even Fox was 52% negative.
The third is so open-ended that I can't imagine discussing it without agreeing on a bunch of specific standards for evidence and discussion, because it requires deciding where objective coverage of badness stops and partisanship starts.
https://en.wikipedia.org/wiki/Newspaper_endorsements_in_the_...
http://archive.news.indiana.edu/releases/iu/2014/05/2013-ame...
https://shorensteincenter.org/news-coverage-donald-trumps-fi...