Your post reminds me of some thoughts I've had about Masses, Elites, and Rebels (which I see get posted on these lemmy instances virtually every time the topic of deprogramming liberals is discussed). Your post is broader -- about deferring to consensus in general as opposed to doing so for Western imperialist lies in particular -- but I think the concept of moral licensing Roderick Day touches on is relevant here.
First, from the essay linked above (italics from the original text):
Talk of “manufacturing” and “inventing” suggests an imposition over and against the individual’s will. I believe that, on the contrary, the process of Western propaganda is better understood in terms of “licensing”: the issuing of moral license for the bourgeois proletariat to profitably go along with bourgeois designs without the feeling of shame overwhelming. In this alternative account people aren’t “brainwashed” insofar as they don’t actually believe the lies, not in the way that we generally understand belief. It’s more correct to say that they go along with them, whether enthusiastically or apprehensively, because it’s actually their optimal survival strategy. When we concede that the time horizon and scope of responsibility within which we all make our decisions varies, it becomes much easier to see how their choice could be smart and intelligent. The enlightened critic can plead that if we all agreed to denounce the status quo in unison we’d be immensely rewarded, but the average worker in the first world cannot be accused of naiveté for preferring to keep a low profile, particularly after being subject — very often by that same critic — to so many grim stories of murder and of punishment and of how any attempt at radical change always goes awry.
Compare to this paragraph from your post:
I do not know about other people, but for me, belief is not really a choice. I believe things because I am convinced of them, and I am convinced of them because I have seen, read, or heard an argument that made sense to me. At least in the way my own mind works, the consensus-divining rod cannot, by itself, lead me to believe something.
With moral licensing in mind, it's not so surprising why the wielders of the consensus-divining rod "believe" the way they do. While the essay only discusses the granting of moral license, I don't think it's a stretch to assert that the withholding/revoking of moral license from those who go against consensus also influences their beliefs.
When most of your support network supports the consensus out of material benefits and/or fear of ostracization, going along with the consensus -- hell, even refusing to look into evidence that might contradict the consensus -- can be perceived as necessary as a survival mechanism. Even if someone's access to basic necessities like food and shelter aren't on the line, ridicule can wear down on you fast when its coming from seemingly everyone you know.
As a side note, "consensus divining rod" is super cool and evocative name for this kind of mentality.
