From a Washington Post analysis by Philip Bump headined “Carlson hates Trump but needs his base—-like the rest of the right”:

My first reaction upon seeing the text message in which Tucker Carlson declares that he “hate[s] [Donald Trump] passionately” was to try to assess the validity of that assertion.

The Fox News host is prone to both hyperbole and hyperventilation, and, at a glance, it’s not clear that this isn’t that. This is quite literally an expression of passion! Is he venting? Is this maybe just another bit of telling his audience (in this case, a colleague) what he thought his audience might want to hear?