Not sure I agree. Some propaganda probably just wants to rile up the base. It's also possible to change which issues seem most salient/urgent/etc. without act

Not sure I agree. Some propaganda probably just wants to rile up the base. It's also possible to change which issues seem most salient/urgent/etc. without actually changing anyone's mind. E.g. Democrats typically care about police brutality, and the environment, but they probably thought more about the former a few years ago and the latter more in 2019, even though AFAIK the actual issues haven't changed much.