From my perspective, mainstream media leans to the right. In general I think it's fair to say that mainstream media--media big business--is above all corporatist. Very few newspapers, magazines, or tv stations are not owned by rich people or large corporations, and even fewer are not supported by ad revenues or "donations" from these same folks. The wealthy and large corps will always have an outsize voice in our media, just as they do in our govt.Sadly main stream media has given up any pretense of objectivity, actively rooting for the left.
Might be the biggest problem, but it's not the only problem. I'm sure I made more than a few posts here years ago about their incredibly biased news coverage of the 2nd Iraq War. Every rumor of WMD was breathlessly reported, and nary a retraction was issued. And there have been other stories more recently that Fox has meticulously avoided reporting on for political reasons.The biggest problem with Fox News is that there are people who confuse their evening op-Ed shows as fox reporting news.
Fox did have a great polling team, but they took care of that little issue after 2020.