When I was growing up, in suburban Detroit, my parents insisted on buying domestic cars. I once asked my dad why. He told me that having a foreign car in our garage would be an insult to our neighbors, a message that they were failing at their jobs. With that in mind, here's Barack Obama's latest ad in Michigan:
To outsiders, it's a straight gotcha/out of touch rich guy message: McCain told a Detroit TV station, "I bought American all my life," when in fact he owns three foreign cars. (This hit is less than perfectly clean: It's possible McCain thinks "I bought American" means that he buys American cars in addition to others, not that he buys American cars exclusively, which is how I always understood the phrase.)
But the real impact of the ad is to hit McCain as a foreign car-buyer, which means somebody who doesn't believe in Detroit and is willing to let the auto industry drown, along with and all the industries that rely on it. There's an emotional resonance to this that most people in other parts of the country don't relate to.