If we take "psy-ops exist"(In my head, "propaganda" is a type of psy-op, but I would not disagree if you drew the circle tighter than that) as a prior, I would have to ask why in the world congresspeople would not be subject to them, both to those that target a broader population, which they are still undeniably part of, and to those that target policy-makers specifically, because if you had the power to influence people, it seems obvious to me that you would target those that gave you great leverage.