As this article says, Sinclair owns the largest number of television stations in the country, and has consistently used its ownership powers to promote the conservative agenda and squelch dissenting viewpoints. If the media ownership rules are changed, this will only get worse.
I used to work for an attorney in the area of communications law. Part of my job was to file for broadcast license renewals with the FCC. It was already frightening enough to find just how extensively these owners are in bed with one another. There are already de-facto monopolies in many parts of this country; the same names crop up time and again. Consolidation will make it even more extensive, and let them come out in the open.
If we progressives learn anything from this election cycle it's that we've gotta push and keep pushing. For better or for worse, it seems we've been asleep at the helm, these past two decades, and the wolves came in through the back door. Even as they took over the airwaves, they've been able to distort the truth to make it seem like we're the ones who dominate the means of discourse. Unless we take this fight all the way to the top, we may find ourselves silenced altogether.