Given that Western political systems are basically a Darwinian selection process, I would be greatly surprised if the political consultants didn't have a good idea about the effectiveness of their propaganda. They certainly gather and examine the data. Of course, there is not much incentive for them to publish their results.
Do you have any reason to believe that political consultants are particularly stupid?
Political consultants make money by convincing politicians that they are useful, not by actually being useful.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.