The corporate media does not do what it does because it is motivated by liberal ideology. It is motivated by profits. It runs stories that are good for ratings. Being moderately supportive of social liberalism tends to be good for ratings, as does justifying every conservative atrocity with a healthy dose of "both sides do it!" commentary.
MSNBC kicks off every day with three hours of right-wing commentary by Joe Scarborough. CNN hired Corey Lewandowski immediately after the Trump campaign fired him. Chuck Todd regularly hosts a series of conservative pundits, who have been reliably wrong about virtually everything for years, and allows them to continue to peddle nonsense without making an effort to call them on their bs (balance!). You will never see a real liberal brought onto these programs at the same time as "thoughtful" conservatives like David Brooks, Bill Kristol, Ron Fournier, or Michael Gerson, because if their false equivalencies were exposed for what they are, or if people were reminded of the lies and vitriol they pushed during the Bush years, they'd start seeing their "both sides do it it" narrative for what it is. The MSM has for years helped cover up the fact that the Republican base and their elected representatives are truly unglued and incapable of competent governance. Trump owes them big time.
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