"[Fox News] has been celebrating a 44-month consecutive streak as the most-watched network on basic cable and a 218-month streak as the most-watched cable news network, averaging 3.5 million primetime viewers and 2 million total-day viewers, according to Nielsen Media Research."
For terrestrial broadcast television in the US, the pro-Trump Sinclair-owned stations possesses 294 stations for around 75% penetration of total US households.
Also, news-talk stations are right-wing with the exception of NPR and sports.
Therefore, one can conclude the right-controlled media is mainstream media.