> Propaganda is not a tidal wave that comes crashing down on established opinions, it is a steady stream that eats at solid rock until it creates a deep gorge you could not have imagined structured in any other way.

Yes. However, they swing things in a single election cycle for marginal supporters of a candidate [which are the folks that really control the outcome in the US. The majority of the states are consistent.].

http://www.luc.edu/quinlan/stories/archive/why-attack-ads-wo...

> Roughly 14 percent of the students said the attack on their candidate made them support him even more, the researchers found. But an equal percentage of students said the advertisement weakened their support and caused them to move closer to the opponent—the one who ran the negative ad.

http://usatoday30.usatoday.com/tech/science/columnist/vergan...

> •Just giving medical students pens with a drug's name on them made the students significantly more favorably disposed toward the medication than otherwise, despite their immersion in classes aimed at letting them rationally evaluate drug benefits, found a 2009 Archives of Internal Medicinereport.

> •Remember shaking hands with Bugs Bunny at Disneyland? Roughly a third of people presented with a fake ad depicting a visit to Disneyland that featured a handshake with Bugs later remembered or knew the meet up with the 'wascally wabbit' had happened to them, according to a 2001 University of Washington study. Even though Bugs is owned by Warner Brothers and verboten at a Disney facility, so it couldn't have happened.