It appears they are really working the polls to get the narrative they want; CNN poll for one they used this last week. If you look at the poll you linked to the Bloomberg poll skewed the avg. If you plugged in the NBC poll instead it would look more consistent. Megan is working real hard to be the one to claim that she took Trump down.
I definitely believe that there is a coordinated effort to construct a narrative that results in serious damage to his run.
I have continued to watch Megyn Kelly’s show despite the fact that I find her repugnant, because her show seems to be the focus point for that effort for Fox, at least in the evenings. I don’t really know what goes on with Fox during the daytime, but I am sure others are doing what they can to assist.