Guess what... people, often without knowing shift their accent to suit their audience. Lord knows I do it... or have been told so.
If people are going to hyperventilate every... single... time... that Hillary opens her mouth, I really recommend investing in a paper bag company.
It's not a hyperventilation. It's showing you what a GOP candidate would be mocked ad nauseum for and derided as "fake" when she gets essentially a free pass. I'm surprised TheHill.com, a far-left outlet, covered this
I loathe fake folksiness because most of the time it's intended to deceive by presenting the person as someone they're not. George Bush, for instance, really made people think of him as some sort of folksy Texas cowboy who lived on a ranch, instead of a spoiled New England / Yale dynast.
With Hillary, everyone knows she doesn't have a southern accent normally and of course she knows no one is going to think she speaks this way normally. So it's more of a personality quirk than a misrepresentation. Lief's link is actually correct... When I find myself in a group of people with a certain lingo/slang or accent, I've found myself adopting the same before too, because that is just how communication happens in that group. Of course, I don't know if code switching is Hillary's reason because I'm not her, but that seems like the most likely cause.
