Barack Obama is adept at code-switching -- the deliberate or unconscious use of different linguistic tropes among different people -- and it's something he's been criticized for, on the grounds that it shows he's insincere. But the fact is that code-switching is a pretty common phenomenon, especially among middle class black folks. I can remember standing outside of my high school and being informed that I didn't have to "talk all smart" anymore because school was over and taking that advice to heart, because I was a teenager. This isn't a hallmark of "anti-intellectualism," rather it's a way to signify that you're part of a particular culture. The point is that you're supposed to be able to manipulate language to your own ends, not be trapped by it. Politicians of all races do it all the time during elections, hence the resurrection of the same dozen folksy tropes every year, but people tend to notice when politicians code-switch when speaking to black folks.
This interview with Sway of MTV is a pretty good example of Obama's adeptness with code-switching:
What's interesting is that Obama himself definitely changed his speechmaking voice between 2004 and 2008 -- his voice sounds a bit more "identifiably black" than he did as the Keynote Speaker at the Democratic convention. He dropped what Talib Kweli refers to as "that white voice you use when you handle business," the one he uses in interviews with Rachel Maddow and drops in interviews with Sway. The point here isn't that there is a "real Obama voice" but rather that his experience with language is rooted in the culture and class experience of the black middle class, especially younger folks who are used to moving through different worlds.
There's nothing really remarkable about this, except that Obama has to be the only presidential candidate I've ever seen who seems really relaxed about code-switching when speaking to a younger, pop culture oriented audience -- here he manages to sound like your cool uncle or your big brother even though he's so close to being president of the United States. There's been a lot of discussion about how Republicans use race in forging a political identity, but what's more interesting in some ways is how Obama has used race to his advantage, this being one example.