I often wonder about these dynamics. I've been genuinely befuddled to learn that some people believe political arguments that I perceived to be so stupid that they had to be part of a cynical political narrative. But lo and behold, some people who I otherwise knew to be reasonable still believed them.

My suspicion is that it only takes a very small minority of a political group to understand the landscape of an issue, initiate a narrative around a power play and have it spread like wildfire within the group.

In short, I think both of your explanations can be correct at the same time. A small subset initiates, the rest of the group genuinely adopts.