I think I am the only one who regularly (if occasionally) points out that the Fox lineup is filled with people who used to be prominent on CNN.
The proliferation of weird right wing media outlets has pushed this discourse to the back burner, a bit, but back in the day it was accepted by all (including people who knew better but pretended not to) that CNN was on The Left just like Fox was on The Right, with the existence of the former justifying the existence of the latter.
How did all those lefties so easily transition into their new jobs, welcomed warmly by their new colleagues? Mystery.