You don't seem to make a point about what specifically the cognitive blindspot is. I infer, perhaps in err due to my lack of comprehension, that you feel the author was somehow wrong to mention Trump here, or perhaps that failing to mention Trump's predecessor is an indication of a blindspot.

Politics is a great area for cognitive blind spots. Sometimes we get so wrapped up our support or opposition that we forget to build the arguments we make from sound foundations. Or our blind spots might just confuse us and leave us not making clear points at all, instead of fallacious ones.

It was unnecessary for the author to mention Trump in the article. It can even be considered detrimental, if the goal was to convey the points in the rest of the article. By mentioning a divisive figure the author undermines his ability to communicate the main points of the article. The figure diverts even intelligent people into discussion of the person mentioned as a trigger for his thoughts for the article, instead of discussion of the article.

That is why the author was wrong to mention Trump in the article.

However, if you're conveying some other point, it fails to reach me. Is it that the author is wrong to say what you yourself feel about the sitting president because earlier presidents did similar things? That the author should also give focus to past presidents who left office years ago and mention them as well or instead? Something else? I can only speculate, which usually ends badly.

The author's inspiration for the article seems to come off earnestly. It is natural for person whose actions and words are amplified and widely disseminated, and who has a lot of power, to inspire thoughts. The man's predecessor has been out of office for years now and is no longer in the same position of power. It would seem a bit disingenuous for the author to quote the previous president as inspiration for his new article, unless there was some particular recent event that caught his attention.

To some, this reply to the article might appear as if it were the result of a polarization tactic that has some historical precedent [1] in other countries. The political leaders would encourage and engage in arguments that attempt to discredit their opponents through claims of hypocrisy, without actually refuting anything. It's a variant of the tu quoque fallacy. If a leader can convince his base, through example and repetition, that this type of fallacy is a valid way to argue, it provides them a form of inoculation against other forms of reason and logic that might sway away their support. It can spread like a meme (in traditional sense) and serve as the basis for their own arguments.

It's very difficult to point out this sort of instilled behavior without offending people. And it's impossible to make a definitive determination with any kind of accuracy. Often people make accidental fallacies that are not indicative of their typical mode of argument. And even if that's their normal mode, it doesn't mean that it's something new to them, or instilled. So to be clear, I am not claiming your argument is the result of the deliberate introduction of this behavior. I have no way to know. It's something each person needs to understand for themselves.

But if an intelligent person who generally does not rely on fallacy were to begin to use them them increasingly, they might not be aware that they were doing so. If it were pointed out, they might deflect and ignore, or believe it was an accident. It would take repeated incidents for them to see a pattern. And once they saw a pattern, they wouldn't immediately associate the behavior as something that was introduced to them over a span of years of consumption. They wouldn't go back and look at the past media they consumed with a new awareness to try and determine the prevalence with which they saw similar argument and behavior.

The natural human response to this sort of suggestion is to reject it. My hope is that a person who has an self-inspecting mind that thinks about the way it thinks might eventually see this in themselves. I have a _ton_ of behaviors that have are instilled in me. I know about them, have conscious awareness of them, but don't always stop them. My go-to swear word is 'Jesus', even though I stopped attending church when I was 14. I know that I can't _really_ make people think more about their own minds with just a few words on the internet, but sometimes I do it anyway.

I can't tell if this post was a valid indicator or not; even if I knew you directly and for years, I wouldn't be qualified to say. People have to be the expert on themselves. I'm just proposing a thought for your own consideration. If the idea of thinking about the way you think is somehow upsetting or angering, then try to find out why that is. In the spirit of your affirmation that intellectual humility begins at home. I hope that you look beyond the surface thought of just "that anonymous person is irritating" and figure out exactly what it is that's so irritating. Then find out why that irritates you so much. And is it a valid reason to feel that way?

[1] https://en.wikipedia.org/wiki/Whataboutism