You're wrong. The only reason that the Democrat Party was able to over the course of less than 20 years, even though a large number of the same politicians were part of their party, turn around the perception that they were the party of racism, Jim Crow, and Segregation, is because of that media control.
That would not be possible in the here and now, because their monopoly on media has been broken.
First off, both the actual truth, and what people perceive as the truth matter.
Second, the riots, the killings, and the mass destruction of property, all of these things are hurting the left. Why? Because the truth is getting out, and the media can't control the narrative as tightly as they used to be able to.
Biden is visibly in mental decline, that is the truth. And that is hurting the Democrats, regardless of what narrative the media is trying to spin, another piece of evidence that the actual truth does matter.
Just because you're letting the leftist media dominate you, doesn't mean that everyone else is.