Just today I came across
this really good article, which explains things quite well, I think.
That's going to understandably be tl;dr for a lot of people, so I'll try to give it my own spin.
On subjects like whether your daughter's soccer game starts at 5 pm or 6 pm, you'll mainly just be interested in getting the right answer. If you mistakenly think it's at 6 pm and someone corrects you, you'll be grateful for the correction.
On subjects like politics, we'll certainly convince ourselves that we are interested in accuracy, but at least subconsciously, we may be more interested in other things.
For many, our subconscious thought process will be something like: "I am going to express my opinion on this topic in order to signal my loyalty to the conservative [or liberal] cause. That way, others who support the same cause will think more highly of me. Maybe we'll bond over it, and we will have each other's backs. That kind of alliance could prove advantageous for all kinds of reasons. I, the subconscious, will therefore work on convincing my conscious self to reaffirm my conservative [or liberal] views so that I can express them more convincingly and reap the benefits."
For me, my tribe isn't really the left or the right, but something more like rationalism. So my subconscious thought process probably goes more like: "I wish to raise my status among my peers, so I will analyze this political issue in a way intended to show off my objectivity and reasoning ability. Then everyone will respect and admire me for it and I'll be really popular. People might even click the Like button on my post!" (I have no idea whether this accurately represents my subconscious thought process -- I have no good way of knowing because it's subconscious. It's just a guess to illustrate one possibility. But note that my guess paints a thought process that isn't particularly likely to be distorted in a way that produces gross inaccuracies. This is not evidence that my thought process isn't particularly likely to be distorted in a way that produces gross inaccuracies. Rather, it is evidence that, like everyone else, my subconscious thought process is very good at representing itself to my conscious thought process as being non-distorting -- without regard for whether that's actually true.)
In other words, on issues where accuracy is all that matters, like what time our daughter's soccer game starts, we're pretty good at evaluating evidence accurately without a lot of subconscious baggage to throw us off. But on issues like religion and politics, we're
all subject to subconscious biases that may cause our reasoning process to go haywire -- from an evolutionary standpoint, it's a feature, not a bug, whose purpose is to bolster our social standing or reputation within our in-group. As a built-in feature designed to go undetected, it's pretty dang difficult to identify in ourselves, much less suppress.
But the fact that somebody has some goofy views about certain political matters says very little about whether he'll be able to figure out what time his daughter's soccer game starts -- or whether Melvin Gordon is likely to get more rushing yards this week than Christine Michael. They just don't have much to do with each other.