I firmly believe that Sarah Palin is a smart, talented public speaker who makes deliberate choices about her use of language to elicit particular responses from different segments of her audience. She's college-educated and has been a professional broadcaster, understanding the nuances of addressing a large audience. She is certainly experienced enough to understand that signifiers like "hockey mom" and "Joe Six Pack" are explicitly communicating to an audience that is white, overwhelmingly not college educated, and lives in rural or suburban areas.
I know because I've been part of that audience. I grew up in an overwhelmingly white part of rural and suburban Pennsylvania, the very same place that many of these attacks are being leveled. I was coincidentally in Greensboro, North Carolina on the same day that Palin first talked about "Real America". I don't have a college education, and I've spent a lot of time around highly-educated professional writers working for the biggest media organizations in the world, and seen their attitudes about language, dialect and vernacular within our country. I've done enough public speaking myself to understand how important word choice, and use of slang, and choice of accent is when speaking to different groups. And it's obvious to anyone who knows American culture why Palin wouldn't identify as a "basketball mom" or talk about "Joe Forty Ounce". These things are not accidents.
Sarah Palin reminds me of George W. Bush in a few ways, but one of the most obvious ones is that they're both dismissed as stupid, as if folksy speech precludes craftiness. "Bush is dumb" was a lot more common than, "Bush is dangerous", and Americans were so distressed by Bush's stupidity that they elected him to two terms. Maybe they're bad in interviews, but on stump speeches, they know exactly what they're saying. I'm fairly sure both Bush and Palin know how "nuclear" is really supposed to be pronounced.