This is a complex topic.
"The media" has been a very easy target for the far left and the broad majority of the right in the US because it tends to dial its reporting, hires, and more towards a sort of middle-left standard. This means even your opposing partisan columnists and commentators are selectively chosen and sparingly used in order to present "both sides" to some issues. Fox News has its two or three primary Democrats and will have the short scream matches between its hosts and liberal representatives. But the content is aimed specifically at stroking the right-wing viewer's opinions.
Then we have CNN and MSNBC. The former loves to see itself as objective. I would agree if every one of their commentators was like a Jake Tapper (a real journalist with integrity, in my view) instead of a Cillizza, Cuomo, or Dana Bash. MSNBC does not even try with hosts like Maddow and O'Donnell. They love to purposefully pick anti-Trump conservatives as their "other side", like John Podhoretz (who I actually respect) and pander to their far left viewership.
Let's see Maddow -- the headliner of MSNBC. Hear about Russia? No? Watch her show. She cannot stop.
"The Intercept conducted a quantitative study of all 28 TRMS episodes in the six-week period between February 20 and March 31. Russia-focused segments accounted for 53 percent of these broadcasts.
That figure is conservative, excluding segments where Russia was discussed, but was not the overarching topic.
Maddow’s Russia coverage has dwarfed the time devoted to other top issues, including Trump’s escalating crackdown on undocumented immigrants (1.3 percent of coverage); Obamacare repeal (3.8 percent); the legal battle over Trump’s Muslim ban (5.6 percent), a surge of anti-GOP activism and town halls since Trump took office (5.8 percent), and Trump administration scandals and stumbles (11 percent)."
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It is an undeniable fact that the media is overwhelmingly aimed towards the left. The reporting on Republican vs. Democratic presidents and candidates should prove this.
Presented is a basic comparison of the polar opposite media well-before President Trump.

And now for the general tone across sources. This is all from Pew Research, as I believe them to be fairly non-partisan.



The liberal spin on bad coverage for the Republicans can be best covered by this snide remark: "The truth has a liberal bias" -- meaning that the press is mostly accurate in its reporting and tone which would naturally lead towards more leftwing positivity. Of course, this is of no importance to the subject.
I think this is view is snarky and wrong. Even if the media can be alleged to be truthful and only reporting more favorably on leftwing matters, the fact is that the other Republican presidents never faced such a backlash as Trump and the current GOP has. Even if they are factually worse, I cannot concede that this is reason enough for the bias to be so heavily slanted against the right.
Now for my final bit of complexity -- the variable of business. The real truth is that "journalistic ethics" ("Democracy Dies in Darkness", as an example) and "sources say" are pandering for a specific benefit: money. There is money in clickbait, hatred, and shocking details. When your president is a bombastic personality with... ahem... a repertoire of the "best words" and the mind of a "stable genius"... clicks are coming in big. Money is made in polarized and breaking news cycles. Washington Post was broke and going under in the last 5 years until Jeff Bezos bought it. Thanks to Trump, subscriptions are sky high for both it and other newspapers, like the NYT.
I ask you this: do IGN editors like making Top 10 articles? Are they list-obsessed millennials? Or do they create them because people click them and make them good for business? Are review scores actually good or just good for business or beloved? There is a level of sheer bias here from newsheads who are left-leaning and also an attention towards the gobs of money in Trump coverage.
Combine market incentives andbias. Voila -- America, 2018.