I don't think these decisions are made at some central Political News Media Headquarters, but it is nonetheless the case that the media can do overwhelming levels of coverage of something, or not.
It's an editorial choice to write, for example, "Joe Biden, facing questions about his mental capacity..." in every single story, or to not do that.
Similarly, every story about Donald Trump from now until the election could read, "Donald Trump, who praised Hitler's generals..." or not.
I'm not even saying that is the right thing to do (and maybe they will do this!), just that sometimes that is how the coverage goes and sometimes it isn't, and this has nothing to do with lofty ideals of journalistic practice.
