How to use ordinary people in political ads.

The great film documentarian Errol Morris -- who makes his living, he says, doing advertisements -- writes about the use of ordinary people in political ads. He surveys some old ads, going back to 1952, and he talks about how he went about using real people to manufacture make an ad promoting Obama:

If you’re not going to put words in people’s mouths, if you’re really listening to what they have to say, you’re going to learn something. Admittedly, the evidence is anecdotal. I haven’t selected these people through some kind of statistical sampling. These people are self-selected. They wrote in and said that they were registered Republicans, Independents or switch-voters who were planning to vote for Obama. People in the middle. And I was interested in talking to them on film about why they were making the switch from voting for a Republican to voting for a Democrat. Was it linked with policy? With the personality of the candidate?

Here's the ad :