Legitimate us of Reductio ad Absurdum?

What I mean when I say emotion and reason are mutually exclusive is that the two are completely independent and can have nothing to do with each other, because if you have a string of thoughts that starts from an emotion I.e. "I hate trump" then any logical thought following isn't really rational, it's ration's cousin who has herpes: rationalization. As for that highlighted part, what I meant to write was "Just because you are doing something rational or thinking rationally does no automatically mean that what you are doing is for rational reasons."

Since reason is to do with cognition and since emotion influences cognition and vice versa then I don't think it's accurate to say they work independently of one another. And when I took of emotion I do not mean "emotional." And yes, cognitive processes are reasoning processes. With all that being said I think I get what you mean when you talk it not being rational to hate trump. I am going to try and simplify what you're saying here and this is also my position in relation to Trump.

So, as an outsider, we can reason as to why another person hates trump based on what they read or hear about. And if a person hears and reads things that outrage them they will likely not think very clearly as heightened emotions clearly lead one to think and/or act irrationally as well as unreasonably and illogically. However, that other person is not coming to conclusions based on good logic; they are coming to them based on emotion which of course is not logical or good reasoning. And then when a person starts coming up with stuff about how it's okay to hate Trump because their emotions dictate it so then that is what I would call being illogical, albeit being illogical is still reason; there is still a cognitive process going on; it's just not very good reasoning. I will come back to the thing about rationalization later on here as it is mentioned again somewhere.

When we think about why we did something in retrospect, I would say that 999/1000 times it is rationalization, and the fact that our decisions are largely unconscious suggests this is true, and everything including our reasoning ability is deterministic.

Since rationalization is to do with making justifications (excuses) for one's behavior and feelings this also entails that one would feel on a deeper level somewhat uncomfortable with their behavior and feelings in order for them to make excuses for them. And retrospection is basically about looking back and making sense of past events (reasoning). Therefore, if we accept that if people are making rationalizations 999/1000 of the time then we also have to accept that 999/1000 of time everyone is in retrospection they are making rationalizations because of a psychological defense mechanism which of course we cannot conclude is the truth. I mean we can believe this is the truth and have our own subjective reasons for doing so but we cannot logically deduce that this is the case. I also find it highly unlikely that more than seven billion people are going into a psychological defense mechanism 999/1000 of the time when they are reasoning about past events and reasoning about past events is something humans do quite often.