Michael Bruter, a senior lecturer in European politics at the school, fed a steady diet of slanted newsletters about Europe and the European Union — either all good news or all bad — to 1,200 citizens of six countries over two years.
Over time, Bruter found, and without exception, the readers subconsciously adopted the bias to varying degrees and changed their view of the EU and of themselves as Europeans, a few of them in the extreme. Surprisingly, they didn't register any change right after the newsletters stopped — not until full six months later, when they had obviously let down their guard.
This, then, is why it matters that, (e.g.) the Sun is supporting the Tories. Not because it can order its readers to vote accordingly, but because it can decide the story it wants to tell them. Then they'll make up their own minds accordingly. But of course, this has to be a somewhat subtle process. Step over the line between impartial judgement and naked character assassination, and people quickly start to question the quality of the information your feeding them. And in the present case, it seems the Sun has made people think better of Gordon Brown, which is no mean feat nowadays. But only, I suspect, as far as that one story goes. In one month's time, this incident will be firmly in the past but the one-sided narrative, and its effect on voters, will remain. The best way to destroy reputations is erosion, not demolition.